Surface- and interlayer-modified ammonium vanadate cathode for high-performance aqueous Zn-ion batteries

Vanadium-based compounds suffer from the poor intrinsic conductivity, unstable structure, and sluggish reaction kinetics as the cathode materials for aqueous zinc ion batteries. In this work, conductive polymer (polypyrrole, PPy) coating/pre-intercalation is proposed to achieve stable and reversible Zn2+ storage in ammonium vanadates (NH4V4O10, NVO). The PPy coating on the surface of the NVO nanobelts effectively suppresses material dissolution, and promotes the desolvation of hydrated zinc ions at the interface. The intercalated PPy within the layered structure expands the interlayer spacing, induces the formation of oxygen vacancies, and increases the electronic conductivity, thus accelerating zinc ion diffusion and electron transport kinetics. Benefiting from simultaneous optimization of the surface and interlayer structure, the PPy-NVO electrode demonstrates outstanding electrochemical properties, delivering a high discharge capacity of 455mAh g-1 at 0.1 A g-1 and 250mAh g-1 at 5 A g-1, maintaining 89 % of its initial capacity after 2500 cycles at 4 A g-1. Ex situ characterization techniques demonstrate the reversible Zn ions insertion/extraction storage mechanism in the PPy-NVO cathode.

Domino-like turn-on chemiluminescence amplification: Opening a gateway through proximal-imidazole species formation and metal-ligand complexation

Due to their extremely low background signal and high sensitivity, the chemiluminescence (CL) probes have received a great attention in various chemical and biological applications. However, the lack of selectivity is still a challenging task. As an innovative topic of research, in this work we developed a domino-like turn-on CL reaction through proximal-imidazole species for the first time. The oxidation reaction of N-(2H-[1,2,4]thiadiazolo[2,3-a]pyridine-2-ylidene)benzamide (1) by hydrogen peroxide found to promoted by a domino-like reaction between proximal imidazole species and the Co2+-1 complex formation which accompanied by a dramatically turn-on emission. In the way of explaining the possible mechanism, the application of density functional theory (DFT) studies revealed that there are three possible pathways for the reactions between precursor 1 and HOO- in the presence of imidazole to produce the oxidized isomers. The strongest interaction found to occur in pathway 3, in which the sulfur atom was oxidized, while there was some repulsion between HOO- and 1, due to the effects of two different charges in pathways 1 and 2. To confirm tits applicability, the CL system was successfully applied to highly selective quantification of vitamin B12 in some real samples. The linear dynamic range was achieved from 0.08 to 34 ng mL-1 and the detection limit was evaluated as 0.028 ng mL-1. This new method introduced fluorescence selectivity and CL sensitivity in single technique. It was finally anticipated that the CL amplification through proximal-imidazole species possesses a great potential on tuning various color-emissions based on different metal-ligand complex formations studied.

Force-electric biomaterials and devices for regenerative medicine

There is a growing recognition that force-electric conversion biomaterials and devices can convert mechanical energy into electrical energy without an external power source, thus potentially revolutionizing the use of electrical stimulation in the biomedical field. Based on this, this review explores the application of force-electric biomaterials and devices in the field of regenerative medicine. The article focuses on piezoelectric biomaterials, piezoelectric devices and triboelectric devices, detailing their categorization, mechanisms of electrical generation and methods of improving electrical output performance. Subsequently, different sources of driving force for electroactive biomaterials and devices are explored. Finally, the biological applications of force-electric biomaterials and devices in regenerative medicine are presented, including tissue regeneration, functional modulation of organisms, and electrical stimulation therapy. The aim of this review is to emphasize the role of electrical stimulation generated by force-electric conversion biomaterials and devices on the regulation of bioactive molecules, ion channels and information transfer in living systems, and thus affects the metabolic processes of organisms. In the future, physiological modulation of electrical stimulation based on force-electric conversion is expected to bring important scientific advances in the field of regenerative medicine.

Reprogrammed glycolysis-induced augmentation of NIR-II excited photodynamic/photothermal therapy

Small molecule-based multifunctional optical diagnostic materials have garnered considerable interest due to their highly customizable structures, tunable excited-state properties, and remarkable biocompatibility. We herein report the synthesis of a multifaceted photosensitizer, PPQ-CTPA, which exhibits exceptional efficacy in generating Type I reactive oxygen species (ROS) and thermal energy under near-infrared-II (NIR-II, >1000 nm) laser excitation at 1064 nm, thereby combining photodynamic therapy (PDT) and photothermal therapy (PTT) functionalities. To enhance therapeutic efficacy, we engineered lonidamine (LND) by conjugating it with triphenylphosphonium (TPP) cations, producing LND-TPP. This compound inhibits mitochondrial glycolysis and downregulates heat shock protein 90 (HSP 90) levels in a breast cancer mouse model, potentiating both PDT and PTT. For in vivo applications, PPQ-CTPA and LND-TPP are encapsulated within the amphiphilic polymer DSPE-SS-PEG to obtain PPQ-CTPAL NPs. In breast cancer cell lines, PPQ-CTPAL NPs are decomposed by cellular GSH, simultaneously releasing the dual-functioning photosensitizer PPQ-CTPL and the mitochondria-disrupting agent LND-TPP. Upon 1064 nm laser irradiation, we found that tumor growth in breast cancer mice is effectively restrained by PPQ-CTPAL NPs. This work highlights the synergistic integration of PDT, PTT, and chemotherapy facilitated by NIR-II fluorescence, photoacoustic, and photothermal imaging under 1064 nm irradiation, underscoring the clinical potential of multifunctional phototherapeutic agents.

Cation vacancy modified bismuth selenide nanosheets toward durable and ultrafast sodium-ion batteries

High-performance metal chalcogenide anodes based on conversion and alloy reaction are promising for the next generation of sodium-ion batteries (SIBs) due to their high theoretical capacity. However, the intrinsic limitations of metal chalcogenides, including inadequate electrical conductivity and suboptimal ion diffusion kinetics, impede high-rate performance and large-scale applicability. Herein, a two-dimensional ultrathin Cu heteroatom-doped Bi2Se3 nanosheet with cation vacancies (denoted as DBS) has been developed as an anode for SIBs, exhibiting high capacity and superior rate performance. The electrical conductivity of DBS is enhanced by the contribution of surface topological states and the regulation of electronic structure due to structural defects. Furthermore, the modified crystal structure demonstrates improved ion transport capabilities, elevated Na+ adsorption energy, and a greater number of adsorption sites, as substantiated by density functional theory (DFT) calculations. Consequently, the DBS electrode exhibits reduced polarization potential, fast capacitive charge storage and a more comprehensive conversion-alloy reaction, thereby achieving a high specific capacity (528 mA h g-1 at 0.2 A g-1), large rate performance (383 mA h g-1 at 10 A g-1), and long cycling stability. This superior performance enhances the appealing electrochemical properties of both coin and pouch-type DBS//Na3V2(PO4)3@C full cells.

Engineering the regulation strategy of active sites to explore the intrinsic mechanism over single‑atom catalysts in electrocatalysis

The development of efficient and sustainable energy sources is a crucial strategy for addressing energy and environmental crises, with a particular focus on high-performance catalysts. Single-atom catalysts (SACs) have attracted significant attention because of their exceptionally high atom utilization efficiency and outstanding selectivity, offering broad application prospects in energy development and chemical production. This review systematically summarizes the latest research progress on SACs in five key electrochemical reactions: hydrogen evolution reaction, oxygen reduction reaction, carbon dioxide reduction reaction, nitrogen reduction reaction, and oxygen evolution reaction. Initially, a brief overview of the current understanding of electrocatalytic active sites in SACs is provided. Subsequently, the electrocatalytic mechanisms of these reactions are discussed. Emphasis is placed on various modification strategies for SAC surface-active sites, including coordination environment regulation, electronic structure modulation, support structure regulation, the introduction of structural defects, and multifunctional site design, all aimed at enhancing electrocatalytic performance. This review comprehensively examines SAC deactivation and poisoning mechanisms, highlighting the importance of stability enhancement for practical applications. It also explores the integration of density functional theory calculations and machine learning to elucidate the fundamental principles of catalyst design and performance optimization. Furthermore, various synthesis strategies for industrial-scale production are summarized, providing insights into commercialization. Finally, perspectives on future research directions for SACs are highlighted, including synthesis strategies, deeper insights into active sites, the application of artificial intelligence tools, and standardized testing and performance requirements.

Adaptive microgel films with enhancing cohesion, adhesion, and wettability for robust and reversible bonding in cultural relic restoration

Hydrogel adhesives hold significant promise for applications in flexible intelligent systems and biomedical engineering. However, reconciling high toughness with strong, durable, and repeatable interfacial adhesion remains a daunting challenge. Herein, a new strategy was proposed involving the utilization of physically crosslinked microgels to fabricate a high-toughness adhesive microgel film, optimizing cohesion, adhesion, and wettability to significantly enhance interfacial adhesion performance. The microgels were synthesized using polyzwitterions and acrylic acid through inverse emulsion method, leveraging on their intrinsic ability to readily form abundant non-covalent interactions. The resultant microgel-based adhesive film, formed through physical crosslinking and chain entanglement mechanisms, exhibited a tensile strength of 0.34 MPa, an exceptional elongation at break of 1107.79 %, and a toughness of 2842.17 kJ/m3. Furthermore, this adhesive film demonstrated a remarkable adhesive strength of 1740.9 kPa, with its adhesion performance retaining stable and effective even under extreme environmental conditions, including elevated temperatures and complete submersion in aqueous environments. In contrast to conventional hydrogel adhesives, this microgel system achieves superior mechanical robustness, interfacial adhesion, and environmental resistance, highlighting their promising potential candidate for applications in cultural heritage conservation.

Facile synthesis of a single-atom cobalt catalyst to enhance peroxymonosulfate oxidation to degrade emerging contaminants by visible-light regulation: From radical pathway to synergistic pathway

In-situ modulation of the synergistic effect of both radicals and non-radicals is crucial in the activation of peroxymonosulfate (PMS). In this study, we show a layer-structured carbon nitride with anchored cobalt single atoms was facilely synthesized (0.2Co-CN), followed by an investigation of the mechanism and performance in activating PMS for the removal of emerging contaminants (ECs) assisted by visible light. The results indicate that under visible-light excitation, the catalytic system achieved 97.1% degradation of Norfloxacin (NOR) within 60 min, representing a 3.3-fold increase in kinetics compared to conditions without light. Experimental characterization reveals that the anchored single-atom Cobalt is prone to adsorbing and concentrating PMS, thereby favoring the activation; This observation is further supported by density functional theory calculations. The degradation mechanism shifts from a pure radical pathway to a synergistic pathway involving both radical and non-radical, under in-situ light irradiation. This light-assisted modulation significantly increases both the variety and concentration of reactive oxygen species(ROS), leading to effectively enhanced catalytic performance. The catalyst exhibits robust functionality across a broad pH range without metal ion leaching, possesses unmoved interference resistance without compromising efficiency, demonstrates excellent reusability without significant fatigue, and shows applicability to various ECs and diverse real-world water bodies, paving the road to potential industrial level applications.

A two-pronged G-quadruplex construction strategy enables the development of a two-in-one aptasensor for β-lactoglobulin

Food allergies are a global concern since they threaten human health and are challenging to treat. Avoiding allergen exposure is an effective measure for vulnerable individuals, requiring reliable and simple allergen detection techniques. This can be achieved by integrating aptamer and G-quadruplex (G4) components into a sequence as a smart nucleic acid sensing nanodevice. The challenge lies in the functional structure formation of these components due to the lengthy integrated sequence and its conformational complexities. This study proposes a two-pronged strategy, encompassing both the nucleic acid sequence level and spatial structure levels, to construct a functional parallel G4 for an aptamer-loop-G4 integrated sequence, thereby enabling colorimetric detection of β-lactoglobulin (β-LG). Specifically, through comprehensive tailoring, interfering structures are excluded, and the integrated sequence is modified to adopt an appropriate G4 conformation to enhance signaling efficiency. Additionally, the topologically guided combined use of Mg2+ and K+ ions coordinates the conformational folding of the aptamer and G4 components, ensuring the recognition capacity of the aptamer. Finally, a β-LG aptasensor is established that presents advantages, such as cost-efficiency, simple operation, 35-min rapid detection, excellent specificity, and sensitivity for a linear range of nearly four orders of magnitude, meeting point-of-care testing (POCT) requirements.

Multifunctional nanozymatic biosensors: Awareness, regulation and pathogenic bacteria detection

It is estimated that approximately 700,000 fatalities occur annually due to infections attributed to various pathogens, which are capable of dissemination via multiple environmental vectors, including air, water, and soil. Consequently, there is an urgent need to enhance and refine rapid detection technologies for pathogens to prevent and control the spread of associated diseases. This review focuses on applying nanozymes in constructing biosensors, particularly their advancement in detecting pathogenic bacteria. Nanozymes, which are nanomaterials exhibiting enzyme-like activity, combine unique magnetic, optical, and electronic properties with structural diversity. This blend of characteristics makes them highly appealing for use in biocatalytic applications. Moreover, their nanoscale dimensions facilitate effective contact with pathogenic bacteria, leading to efficient detection and antibacterial effects. This article briefly summarizes the development, classification, and strategies for regulating the catalytic activity of nanozymes. It primarily focuses on recent advancements in constructing biosensors that utilize nanozymes as probes for sensitively detecting pathogenic bacteria. The discussion covers the development of various optical and electrochemical biosensors, including colorimetric, fluorescence, surface-enhanced Raman scattering (SERS), and electrochemical methods. These approaches provide a reliable solution for the sensitive detection of pathogenic bacteria. Finally, the challenges and future development directions of nanozymes in pathogen detection are discussed.

Advancements in membrane technology for efficient POME treatment: A comprehensive review and future perspectives

The treatment of POME related contamination is complicated due to its high organic contents and complex composition. Membrane technology is a prominent method for removing POME contaminants on account of its efficiency in removing suspended particles, organic substances, and contaminants from wastewater, leading to the production of high-quality treated effluent. It is crucial to achieve efficient POME treatment with minimum fouling through membrane advancement to ensure the sustainability for large-scale applications. This article comprehensively analyses the latest advancements in membrane technology for the treatment of POME. A wide range of membrane types including forward osmosis, microfiltration, ultrafiltration, nanofiltration, reverse osmosis, membrane bioreactor, photocatalytic membrane reactor, and their combinations is discussed in terms of the innovative design, treatment efficiencies and antifouling properties. The strategies for antifouling membranes such as self-healing and self-cleaning membranes are discussed. In addition to discussing the obstacles that impede the broad implementation of novel membrane technologies in POME treatment, the article concludes by delineating potential avenues for future research and policy considerations. The understanding and insights are expected to enhance the application of membrane-based methods in order to treat POME more efficiently; this will be instrumental in the reduction of environmental pollution.

Nanoscale palladium-Mo6S8/carbon nanowires toward efficient electrochemical hydrogen evolution and hydrogen peroxide detection

Chevrel phase (CP) molybdenum sulfides (Mo6S8) have attracted extensive research attention in the field of energy conversion and storage due to their unique electronic structures and rich open channels. However, comprehensive understanding of intrinsic kinetic mechanisms governing the electrocatalytic bi-functional hydrogen evolution reaction (HER) and hydrogen peroxide (H2O2) sensing on CP-based composites is still lacking. Herein, nanosized palladium (Pd) and Mo6S8 particles were assembled in carbon nanowires (C NWs) via electrospinning followed by pyrolysis. The as-obtained novel Pd-Mo6S8/C NWs exhibited excellent performance in terms of a low overpotential of -194 mV at η10 for HER, and an ultrahigh sensitivity of 2231 μA mM-1 cm-2 with a limit of detection of 25 nM for H2O2 sensing. The experimental and theoretical findings demonstrated that Pd and Mo6S8 nanoparticles (NPs) exhibited exceptional catalytic activity and strong electronic interactions. The synergistic effects of these two components could effectively modulate the binding strength of reactants and intermediates on the catalyst surface, ultimately leading to improved electrochemical catalytic performance toward reduction of small molecules. Moreover, verification of the stable tolerance in various environments and good selectivity of the electrocatalyst promoted the further use of Pd-Mo6S8/C NWs-based electrochemical sensing system for sensing additional H2O2 in milk samples, proving the widespread potential of this material for practical applications. This study significantly advances the understanding of nanoscale and bi-functional CP-based composites.

Label-free turn-on electrochemiluminescence assay of β-glucuronidase at single-electrode

Electrochemiluminescence (ECL) has achieved significant commercial success over the past few decades across various fields, particularly in the healthcare industry. The measurement scheme oftentimes involves target recognition elements (e.g. catching antibodies) labeled with a suitable ECL luminophore (e.g. tris(2,2'-bipyridine)ruthenium(II))). While this approach realizes the ultrasensitive detection of various biomarkers, it is somewhat complicated strategy for certain targets such as enzymes. In this study, β-glucuronidase (B-GLU), a promising biomarker and a common water/foodstuff safety indicator, was quantified by measuring the ECL signal of fluorescent product generated from non-fluorescent substrate by the B-GLU enzyme. To this end, hot electron-induced ECL of three luminophores (fluorescein, 4-methylumbelliferyl and resorufin) that are used as building blocks to synthesize various commercially available non-fluorescent substrates was compared for the first time. To increase the appeal and practicality of this approach, the common multi-well assay format was adapted to the present type ECL by carrying out the ECL reactions at single carbon black/polystyrene electrode. In this electrochemical setup, multiple cells were fabricated on the surface of a poorly conducting substrate by attaching Teflon tape with multiple holes to the substrates surface. Sample throughput time decreases considerable as target, blank and sample signals can be simultaneously obtained from the electrochemical cells when voltage is applied across the single electrode. The detection limit for B-GLU after 2 h of incubation was 0.07 U L-1 when 4-methylumbelliferyl-β-D-glucuronide was used as the fluorogenic substrate and Br- was used as the co-reactant. B-GLU recovery rates from diluted saliva with the present ECL approach were adequate (93-103 %) and similar to those obtained with the fluorescence technique.

Monitoring variations in mitochondrial hydrogen sulfide using two-photon cyclometalated iridium(III) complex probe: A new strategy for ischemia-reperfusion drug discovery and efficacy evaluation

Hepatic ischemia-reperfusion injury (HIRI) is one of the main causes of liver insufficiency and failure after liver surgery. However, the effectiveness of current methods of treating HIRI is generally limited. Previous studies have shown that hydrogen sulfide (H2S) has a beneficial effect on HIRI, and an appropriate concentration of H2S can significantly reduce HIRI by protecting the mitochondria. Therefore, establishing an accurate imaging platform for monitoring variations in mitochondrial H2S is an effective strategy for anti-HIRI drug discovery and efficacy evaluation. To this end, a cyclometalated iridium(III) complex-based probe, Cym-Ir-EDB, was developed for detecting mitochondrial H2S in HIRI. Cym-Ir-EDB possesses good sensitivity, high selectivity, negligible cytotoxicity, and excellent mitochondrial-targeting ability, rendering it a promising imaging tool for analyzing variations in mitochondrial H2S in HIRI cells. Using Cym-Ir-EDB as a probe, anti-HIRI drugs were screened from isothiocyanates by monitoring variations in mitochondrial H2S in HIRI cells, for the first time. Moreover, the dynamics of mitochondrial H2S in HIRI cells were visualized and the response of HIRI to treatment with the screened erucin was monitored. The findings indicate that Cym-Ir-EDB can serve as a useful imaging platform for the precise imaging of mitochondrial H2S in HIRI, thereby contributing to anti-HIRI drug discovery and efficacy evaluation.

Stabilizing high-rate potassium storage by ferromagnetism

In this work, pre-magnetized ε-Fe2O3 was used as prototype electrode material to reveal the synergetic effect between ferromagnetism and electrochemical performance. Upon high-rate potassiation, ε-Fe2O3 was unable to fully participate in conversion reaction due to "potassiation retardation". The higher the rate was, the less complete the conversion reaction became. The as-converted Fe product was magnetized by the remanent magnetization of residual ε-Fe2O3 and underwent a magnetic decantation process. As a result, the Fe phase was magnetically attached to the residual ε-Fe2O3 surface, while the diamagnetic K2O phase was separated out. This phase separation not only suppressed the generation of KOH but also made side reactions involving - COOK species less likely to occur, thereby avoiding a large consumption of electrolyte and stabilizing the solid-electrolyte interphase layer. Driven by this synergy, ε-Fe2O3 showed the best cycling stability on potassium storage at 5 A g-1. Its discharge capacity loss per cycle was as low as 0.094 ‰ from 4 to 700 cycles with Coulombic efficiencies above 99.9 %. Moreover, the results also showed that the rate influence on potassium storage was much greater than that on lithium storage. It was thus anticipated that this work would shed new light on the understanding of interrelated physicochemical properties of electrode material.

Ce-doped NiCoP/ Co3O4 composite Nanostructures on Ni foam and their enhanced performance for water and urea electrolysis

Producing hydrogen through freshwater or urea-containing wastewater electrolysis using renewable electricity requires multifunctional catalysts made from nonprecious metals. In the current study, we disclose the rational fabrication of oxide/phosphide heterostructure nanorods with rare earth metal doping on nickel foam (NF), denoted Ce-NiCoP/Co3O4/NF, via partial phosphorization. Benefiting from intrinsic interface formation and doping effects, the interaction between the coupling components facilitates electron transfer, optimizing the electronic configuration of the Ce-NiCoP/Co3O4/NF catalyst. Ce-NiCoP/Co3O4/NF exhibited a competitive potential of - 0.151 V for hydrogen evolution reaction, 1.50 V for oxygen evolution reaction (OER), and 1.33 V (versus reversible hydrogen electrode) toward urea oxidation reactions (UOR) at 100 mA cm-2. In situ Fourier-transform infrared combined with electrochemical analysis detects *OOH and *O2- intermediates in OER, as well as CO32- and CNO- ions, alongside the N-H vibration in UOR, providing deeper insight into the OER and UOR mechanisms on the Ce-NiCoP/Co3O4/NF. More importantly, the catalyst exhibited an activity of 20 mA cm-2 requiring voltages as low as 1.52 V for unassisted water splitting and 1.27 V for urea-assisted electrolysis.

Construction of a heterojunction between Ni/Al layered double oxides and CdS quantum dots for efficient photocatalytic hydrogen production

The Ni/Al layered double oxide (Ni/Al-LDO) is a promising photocatalyst because of the high surface area and abundant active sites. However, the application of Ni/Al-LDO for photocatalytic hydrogen evolution is hindered by the unclarity of the optimized microstructure and limited light absorption. In this work we report the structural evolution from Ni/Al layered double hydroxides (Ni/Al-LDH) to Ni/Al-LDO, which is able to achieve a precise regulation of the layered structure with abundant acid sites for photocatalysis. Further, CdS quantum dots (QDs) are in-situ grown on the sheet-like Ni/Al-LDO to obtain a close contact 0D/2D CdS-Ni/Al-LDO heterojunction. CdS-Ni/Al-LDO exhibits a hydrogen evolution efficiency of 20.3 mmol/g/h and an apparent quantum yield (AQY) of 22.2 % at a wavelength of 450 nm. The superior performance is attributed to the synergistic effects of abundant Lewis and Brønsted acid sites of Ni/Al-LDO, the layered structure with a high specific surface area and the heterojunction between Ni/Al-LDO and the CdS QDs.

Metal effect boosts the photoelectric properties of two-dimentional Dion-Jacobson (3AMPY)(MA)3M4I13 perovskites

Two-Dimentional (2D) Dion-Jacobson (DJ) perovskites are emerging photovoltaic materials due to their excellent rigid structures and improved environmental stability compared to 2D Ruddlesden-Popper (RP) perovskites. Herein, we adopt 3-(aminomethyl)pyridine (3AMPY) as the divalent interlayer spacer to alleviate the toxicity of lead and explore more highly potential DJ alternatives, the optoelectronic and photovoltaic performance of lead-free DJ (3AMPY)(MA)3M4I13 perovskites are investigated by first-principles calculations, where the central metals are considered as Ba, Cd, Cu, Ge, Mg, Mn, Ni, Sn and Zn to replace Pb. Our findings reveal that introducing Mn, Cd, Ni, and Ge can effectively tune the bandgap within the optimal range of 0.90-1.60 eV for solar cell application. Notably, (3AMPY)(MA)3Ni4I13 exhibits the most favorable optical response capacity, with the light-harvesting efficiency maintaining 80 % in the UV-Vis range. (3AMPY)(MA)3Ge4I13 displays the most excellent carrier transport with electron mobility as high as 555.43 cm2 V-1 s-1, exhibiting a great advantage over 2D perovskites. The predicted photovoltaic performance shows that (3AMPY)(MA)3Mg4I13 possesses the largest open circuit voltage (VOC) (2.12 V), (3AMPY)(MA)3Ge4I13 has the highest short circuit current density (Jsc) (38.90 mA/cm2), and (3AMPY)(MA)3Mn4I13 is with the highest power conversion efficiency (PCE) of 22.55 %. The metal substitutions with Cd, Ni, and Ge show promoted photovoltaic potential over (3AMPY)(MA)3Pb4I13. These results form a basis for broadening the potential candidates of this 2D DJ series in photovoltaic perovskite solar cells (PSCs).

Cationic porphyrin-based covalent organic frameworks for enhanced phototherapy and targeted chemotherapy of bacterial infections

Bacterial infections significantly impede wound healing and threaten global public health. Porphyrin covalent organic frameworks (COFs) have shown promise as phototherapy antibacterial materials. However, the inherent π-π stacking interactions between the monomers also lead to aggregation and quenching of photosensitizers, thereby reducing the production of singlet oxygen (1O2) and compromising their antibacterial efficacy. Herein, we designed and prepared a novel cationic porphyrin-based COFs nanoplatform (TAPP-VIO), utilizing photosensitive TAPP and cationic VIO as structural units. This multifunctional nanoplatform is specifically tailored for targeted phototherapy and chemotherapy against bacterial infections. Upon irradiation, TAPP unit in TAPP-VIO generates heat and 1O2, which effectively disrupt bacterial structure and cause cell death. The incorporation of VIO unit introduces electrostatic repulsion between layers, mitigating π-π stacking effects and enhancing 1O2 production. Additionally, the positive charge imparted by the VIO unit enables TAPP-VIO to bind efficiently to negatively charged bacterial surfaces, immobilizing the bacteria and reducing their motility, thereby improving the overall efficacy of phototherapy. Under identical experimental conditions and concentrations, TAPP-VIO exhibits a 1O2 generation capacity that is 179 % higher than that of nonionic porphyrin COF. Moreover, the temperature increase induced by TAPP-VIO is 85 % of that observed with nonionic porphyrin COF (TAPP-MMA-Da), which is conducive to enhancing the phototherapeutic effects while minimizing heat-induced damage to healthy tissues. In summary, our study presents a straightforward approach to developing non-antibiotic antibacterial nanoagents, and the as-prepared TAPP-VIO is a promising candidate drug suitable for clinical trials in the future.

Enhancing the electrochemical conversion of carbon dioxide to value-added products on zinc oxide-MXene nanocomposite

Developing efficient and sustainable catalysts for CO2 electroreduction is critical to addressing the rising atmospheric CO2 levels and mitigating climate change. This study presents a novel ZnO-MXene (Ti2C) nanocomposite as a high-performance electrocatalyst for CO2 conversion, offering a strategic approach for generating valuable carbon-based feedstocks. The ZnO-MXene nanocomposites were synthesized via the wet impregnation method and comprehensively characterized using X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FTIR). Electrochemical performance was assessed through linear sweep voltammetry (LSV), cyclic voltammetry (CV), and controlled potential coulometry, with gas chromatography employed for product quantification. ZnO-MX10 and ZnO-MX2.5 exhibited high selectivity for CH4 (79.3 % Faradaic efficiency, FE) at -0.56 VRHE and CO (76.8 % FE) at -0.78 VRHE, while significantly suppressing competing H2 evolution. The synergistic interaction between ZnO and MXene enhances charge transfer, increases active sites, and improves surface area, leading to superior electrochemical performance. Overall, this work introduces a novel ZnO-MXene nanocomposite with dual selectivity for CO and CH4, enhanced electroactive surface, and long-term stability. Unlike conventional Zn-based catalysts, which exhibit either limited selectivity or rapid degradation, our composite achieves 79.3 % Faradaic efficiency for CH4 and 76.8 % for CO, while suppressing H2 evolution. This unique tunability and stability make ZnO-MXene an attractive alternative to noble metal-based electrocatalysts.

Delafossite-embedded Z-scheme heterojunction photocathode with abundant heterointerfaces for boosted photoelectrochemical performance

Layered delafossite, an inherently p-type semiconductor, has emerged as a highly promising photocathode material for photoelectrochemical (PEC) water splitting. However, its PEC performance and scalability are significantly limited by the shortcomings of conventional photoelectrode fabrication techniques, which often involve inferior physical adhesion or require harsh processing conditions. In this study, a CuxO layer is introduced via in-situ oxidation of a copper foam (CF) substrate to achieve embedded anchoring of delafossite CuFeO2 (CFO), thereby developing a robust embedded CF/(CFO@CuxO) photocathode. This configuration features extensive and strong 3D semiconductor/semiconductor heterointerfaces. The embedded structure significantly reduces the carrier diffusion length to the CF, thereby enhancing photocarrier collection efficiency. Additionally, this unique geometric design provides abundant heterointerfaces with all-round contact, promoting efficient carrier separation while strengthening interfacial binding. Theoretical calculations further reveal the formation of a strong built-in electric field and a Z-scheme heterostructure, which facilitate effective photocarrier separation and transfer while maintaining robust redox activity. Remarkably, the photocurrent density of the embedded CF/(CFO@CuxO) photocathode at zero bias is 2.73-fold higher than that of the traditional sandwich-stacked CF/CuxO/CFO photocathode and 21.55-fold higher than that of the original CF/CFO photocathode. Furthermore, the scalability of this approach is demonstrated through the fabrication of a 100 cm2 embedded photocathode. This work presents a scalable and cost-effective nanofabrication technique for robust photoactive films, enabling efficient and stable PEC water splitting.

Phase-engineered CoP-Co2P/coal-based carbon fibers composite as self-supporting electrocatalyst for efficient overall water splitting

The development of highly efficient electrocatalysts is critical to advancing overall water splitting (OWS). Herein, a self-supporting composite electrocatalyst based on CoP-Co2P/coal-based carbon fibers (CoP-Co2P/C-CFs) is successfully fabricated through phase-engineering. The formation mechanism of precursors is investigated, enabling precise modification of CoP and Co2P composite phases. This phase-engineering minimizes the Gibbs free energy of hydrogen adsorption, thereby enhancing OWS performance. In addition, the specific active sites involved in the OWS reaction are examined to confirm the effectiveness of phase modulation on CoP and Co2P. Furthermore, C-CFs derived from coal exhibit self-supporting properties as well as good acid and alkaline resistances, making them a promising potential candidate for OWS. A two-electrode cell assembled using CoP-Co2P/C-CFs exhibits a low voltage of 1.60 V at 10 mA cm-2 for OWS, superior to 1.64 V obtained using Pt/C//RuO2. This study not only presents a reliable strategy for obtaining phase-engineered cobalt phosphide catalysts but also outlines a novel approach for coal into high-value-added CFs. Consequently, it offers a new perspective for the development of self-supporting electrocatalysts for OWS.

Dual-channel fluorescent probe for simultaneously visualizing ONOO- and viscosity in epilepsy, non-alcoholic fatty liver and tumoral ferroptosis models

Intracellular peroxynitrite anion (ONOO-) and viscosity play a major part in sustaining redox homeostasis, modulating substance transport and signal transduction. Abnormalities in these factors are closely associated with multiple physiological and pathological processes. Nevertheless, due to the absence of appropriate multifunctional fluorescent sensors, concurrent identification of ONOO- and viscosity has not been achieved in many diseases, such as epilepsy and tumoral ferroptosis models. Herein, a new near-infrared (NIR) fluorescent probe (QX-DP) was rationally conceived for concurrent detection of ONOO- and viscosity. QX-DP was highly sensitive to viscosity at 668 nm and ONOO- at 752 nm which exhibited significant "turn-on" fluorescence signals, respectively. Making use of the QX-DP with dual-channel imaging capability, the ONOO- and viscosity elevated levels in brain tissue of epileptic mice were revealed for the first time, and the visualization diagnosis of non-alcoholic liver injury (NAFL) disease model was achieved. Most importantly, the concurrent utilization of viscosity and ONOO- for visualizing tumor ferroptosis has been successfully achieved not only in cancer cells and zebrafish but also in tumor mice models. Undoubtedly, in comparison with detection of a single biomarker, monitoring dual biomarkers at the same time may offer a more sensitive and dependable strategy in the diagnosis and image-assisted surgery of oxidative stress and viscosity related diseases.

Flexible and wearable electrochemical sensors for health and safety monitoring

Environmental safety monitoring is a crucial process that involves continuous and systematic observation and analysis of various pollutants in the environment to ensure its quality and safety. This monitoring encompasses a wide range of areas, including physical indicator monitoring (pertaining to parameters such as temperature, humidity, and wind speed), chemical indicator monitoring (focused on detecting harmful substances in environmental media such as air, water, and soil), and ecosystem monitoring (including biodiversity assessments and judgments on the health status of ecosystems). This review delves deeply into the significant advancements achieved in the field of flexible and wearable electrochemical sensors (FWESs) over the past fifteen years (from 2010 to 2024). It emphasizes the broad application of these sensors in health and environmental safety monitoring, with health monitoring primarily focusing on exhaled breath and sweat, and environmental monitoring covering temperature, humidity, and pollutants in air and water. By seamlessly integrating electrochemical principles, advanced sensor manufacturing technologies, and sensor functionalization, FWESs have opened up new avenues for non-invasive real-time monitoring of human health and environmental safety. This review highlights key developments in sensor structures, including flexible substrates, printed electrodes, and active materials. It also underscores the remarkable progress made in healthcare and environmental monitoring through the utilization of FWES. Despite these promising advancements, this emerging field still faces numerous challenges, such as improving sensor accuracy, enhancing durability, and reducing costs. The review concludes by discussing the future directions in this field, including ongoing research efforts aimed at overcoming these challenges and expanding the applications of FWESs in various sectors.

Application of mass spectrometry for the advancement of PROTACs

The advent of targeted protein degradation technologies, particularly Proteolysis-Targeting Chimeras (PROTACs), enable the selective elimination of target proteins and open up new avenues for the treatment of various diseases. This review delves into the pivotal role of mass spectrometry (MS) in the advancement of PROTACs. MS-based methodologies serve as invaluable tools for identifying PROTAC targets, validating their efficacy, and elucidating ubiquitination sites and protein degradation dynamics. These insights profoundly enrich our comprehension of the mechanisms of action and facilitate the rational design of PROTACs. Furthermore, this review discusses the role of MS in the structural analysis of proteins and the formation of ternary complexes crucial for the activity of PROTACs. The synergy between MS and PROTAC technology holds the promise of groundbreaking advancements in drug discovery by deepening our understanding of the underlying mechanisms that govern PROTAC drug action, thereby promoting the development of innovative strategies for disease treatment.

A novel ratiometric electrochemical assay for detection of formaldehyde in real food samples

This study developed a novel ratiometric electrochemical sensor for detecting formaldehyde content in food. For the first time, we innovatively utilized 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole (AHMT), a traditional colorimetric probe that specifically reacts with formaldehyde, as an electrochemical probe to construct the electrochemical assay. The reaction product of AHMT with formaldehyde exhibits different redox potentials from AHMT, thereby enabling ratiometric detection of formaldehyde. We systematically investigated the electrochemical behavior of AHMT and its reaction product with formaldehyde. Under optimized conditions, this novel ratiometric electrochemical assay demonstrated high sensitivity and selectivity for formaldehyde, with a response linear range of 0.1-20 μM and a detection limit of 21 nM. Additionally, the sensor was successfully applied to detect formaldehyde in various mushrooms and fish, with measured concentrations of 1.34 μg g-1 in shimeji mushrooms, 0.80 μg g-1 in oyster mushrooms, 1.41 μg g-1 in enoki mushrooms, and 1.12 μg g-1 in king oyster mushrooms. For seafood, concentrations of 2.45 μg g-1 in cuttlefish and 0.83 μg∙g-1 in cutlassfish fish were detected. These results were validated against the standard method, underscoring the sensor's potential and reliability for practical applications. This study is anticipated to offer valuable insights for the development of innovative electrochemical sensors for food analysis.

Fluorescent sensor array for rapid bacterial identification using antimicrobial peptide-functionalized gold nanoclusters and machine learning

Bacterial infectious diseases pose significant challenges to public health, emphasizing the need for rapid and accurate diagnostic tools. Here, we introduced a multichannel fluorescent sensor array based on antimicrobial peptide-functionalized gold nanoclusters (AMP-AuNCs) designed for precise bacterial identification. By utilizing the unique electrostatic and hydrophobic properties of three AMP-AuNCs, this sensor array generated distinct fluorescence patterns upon binding to different bacterial species. Machine learning algorithms, including Principal Component Analysis (PCA), Hierarchical Clustering Analysis (HCA), and Linear Discriminant Analysis (LDA), were employed to analyze fluorescence fingerprint patterns and identify bacterial strains with high accuracy. The sensor array achieved 100 % accuracy in identifying six common bacterial species and demonstrated an 86.7 % accuracy in classifying clinical Escherichia coli isolates from urinary tract infections. This AMP-AuNC-based sensor array offers a promising approach for rapid and precise bacterial diagnostics, with potential applications in clinical settings for combating antibiotic resistance.

Hydroxyl and phenyl co-modified carbon nitride-based ratiometric fluorescent nanoprobe for monitoring mitochondrial pH in live cells and differentiating cell death

Monitoring mitochondrial pH and differentiating live and dead cells are crucial for diagnosing cell status. However, most fluorescent probes suffer from limitations such as high cytotoxicity, photobleaching, unreliability, and an inability to differentiate cell death caused by different inducers. Herein, a ratiometric fluorescent nanoprobe was developed by assembling pH-sensitive hydroxyl- and phenyl-co-modified carbon nitride (HPCN) with pH-insensitive Rhodamine B (RB). HPCN was prepared via thermal condensation of phenylguanidine carbonate using NaOH as the melt. The hydroxyl group modification endowed HPCN with improved water solubility and pH-sensitive characteristics, while the phenyl group modification facilitated mitochondrial targeting and DNA staining via hydrophobic interactions. Based on the fluorescence resonance energy transfer (FRET) from HPCN to RB, the nanoprobe exhibited a linear response in the relative fluorescence intensities at 500 nm and 584 nm over a pH range of 4.5-8.5. Benefiting from its low cytotoxicity, excellent reversibility, and outstanding photostability, the nanoprobe was capable of monitoring mitochondrial pH changes in live cells and differentiating live and dead cells, apoptosis and necrosis, and necrosis induced by different agents, regardless of cell type. This work provides a reliable method for diagnosing cell status and cell death induced by various inducers.

Enhanced electrochemiluminescence of mixed-ligand metal-organic framework with suppressed non-radiative transitions for "signal-off" biosensing of β-galactosidase

Organic molecular emitters usually suffer from the aggregation-caused quenching (ACQ) effect, which significantly decreases their electrochemiluminescence (ECL) efficiency. This work designed a straightforward strategy to alleviate the ACQ effect and thus improve the ECL efficiency by employing a donor-acceptor (D-A) type ligand containing benzothiadiazole group and another ligand with identical connectivity to assemble a mixed-ligand zirconium-based metal organic framework (m-Zr-MOF). Upon the formation of a reticular structure and the distance increase between two ligands, the m-Zr-MOF exhibited alleviating ACQ effect due to the suppressed non-radiative transitions, which was confirmed by the improvements of both quantum yield and fluorescence lifetime. At the molar ratio of 3:1 for two ligands the obtained m-Zr-MOFs displayed the optimal ECL performance, and thus an ECL imaging method was developed for "signal-off" detection of β-galactosidase (β-Gal) by combining its enzymatic property to catalyze the hydrolysis of p-nitrophenyl β-D-galactopyranoside, which generated p-nitrophenol to quench the ECL emission through resonance energy transfer. The proposed method showed a detectable range of 5.0 to 2 × 104 mU/L with a detection limit of 1.92 mU/L, much lower than those of reported fluorescence and electrochemical methods. The designed m-Zr-MOF introduced an innovative concept for the development of mixed-ligand MOFs and their application in ECL imaging.

Bridging laboratory innovation to translational research and commercialization of extracellular vesicle isolation and detection

Extracellular vesicles (EVs) have emerged as promising biomarkers for various diseases. Encapsulating biomolecules reflective of their parental cells, EVs are readily accessible in bodily fluids. The prospect for minimally invasive, repeatable molecular testing has stimulated significant research; however, challenges persist in isolating EVs from complex biological matrices and characterizing their limited molecular cargo. Technical advances have been pursued to address these challenges, producing innovative EV-specific platforms. This review highlights recent technological developments, focusing on EV isolation and molecular detection methodologies. Furthermore, it explores the translation of these laboratory innovations to clinical applications through the analysis of patient samples, providing insights into the potential diagnostic and prognostic utility of EV-based technologies.

Ni(II) complexes of His2 peptides as multi-responsive electrochemical probes for anion sensing

Peptides possessing a histidine residue at the second position (His2) exhibit distinctive coordination properties, effectively binding transition metal cations. The resulting complexes, with labile binding sites, offer advantageous features as potential molecular receptors. In this work, a His2 peptide library was designed to select a sequence that, upon binding Ni(II) ions, would exhibit the most promising properties for anion sensing. Electrochemical techniques were used to characterize the redox properties of the studied Ni(II)-His2 peptide complexes. Subsequently, voltammetric responses of the complexes in the presence of various biologically relevant anions (chlorides, sulfates, acetates, lactates and phosphates) were collected and analyzed using Principal Component Analysis, providing effective anion discrimination based on electrochemical fingerprints. Finally, a simple methodology was proposed to differentiate varying lactate and phosphate concentrations in complex, multi-ion samples, simulating physiological and pathological blood plasma conditions. The results confirm the high application potential of the proposed class of molecular receptors and provide insights into novel anion-sensing strategies utilizing metal-peptide complexes as multi-responsive electrochemical probes.

A multifunctional biosensor for linked monitoring of inflammation indicators in hypertension drug evaluation and companion diagnostics

Hypertension, often called the "silent killer", is a prevalent chronic disease closely linked to inflammation. However, most current methods monitor only single indicator, providing a limited view of inflammation in hypertension progression. To address this, we developed a multifunctional biosensor featuring a dual target linked monitoring (DTLM) Probe for the simultaneous detection of IL-6 and CRP, two key inflammatory markers in hypertension progression. The DTLM Probe, based on NH2-UiO-66@AuNPs with mutually non-interfering signal chains, was optimized for high performance in tracking both indicators simultaneously. The dual outputs operate independently, enabling IL-6 and CRP to be detected together or individually within a single sample injection. Under optimized conditions, the biosensor demonstrated excellent specificity and sensitivity, with detection limits of 355 fg/mL for IL-6 and 367 fg/mL for CRP. Applied to a rat model, the biosensor effectively explored the anti-inflammatory effects of Qishenyiqi, a traditional Chinese medicine, assessing its efficacy in reducing hypertensive heart damage. Additionally, it distinguished IL-6 and CRP levels between healthy and hypertensive individuals, capturing subtle changes after treatments. This ensured targeted anti-inflammatory therapies for patients who would benefit most. This biosensor provides a powerful and versatile platform for dual markers tracking, supporting both drug evaluation and companion diagnostics for tailor treatments in hypertension management.

Cysteine-assisted synthesis of copper nanoclusters for construction of FRET-based ratiometric sensor for visual detection of alkaline phosphatase

Abnormal alkaline phosphatase (ALP) levels in the human body are closely associated with various diseases, particularly hepatobiliary diseases and bone diseases. Herein, we constructed a ratiometric sensor based on Förster resonance energy transfer (FRET) using strongly photoluminescent copper nanoclusters (Cu NCs) for the detection of ALP with high sensitivity and specificity. The cysteine-stabilized Cu NCs (Cys-Cu NCs) were synthesized through a ligand-exchange reaction and core-size etching focusing, which displayed bright photoluminescence (PL) with a quantum yield (QY) of 10.5 %. Multispectral characterization indicated that zwitterionic cysteine ligands without obvious steric hindrance could significantly enhance intra/inter-ligand-involved charge transfer, leading to a significant increase in fluorescence emission (∼14 folds) compared to precursor Cu NCs. A FRET-based ratiometric sensor for ALP detection was constructed by combining Cys-Cu NCs with a Cu2+-assisted oxidation reaction of o-phenylenediamine (OPD) to generate fluorescent 2,3-diaminophenazine (DAP). The strong coordination interaction between the ALP substrate and Cu2+ significantly affected the FRET process between Cys-Cu NCs and DAP, thereby altering the fluorescence ratio. Based on the specific response of ALP to its substrate, the ratiometric sensors showed good linear relationship within the range of 0.1-50 U/L, with a detection limit (LOD) of 0.075 U/L. Furthermore, the FRET-based ratiometric sensor was integrated with a polymer hydrogel to fabricate a portable hydrogel sensor for simple and visual detection of ALP.

Sponge-like inorganic-organic S-scheme heterojunction for efficient photocatalytic hydrogen evolution

Covalent organic frameworks (COFs)-based S-scheme heterojunction photocatalysts have gained considerable attention for photocatalytic hydrogen evolution. However, challenges such as limited interfacial contact and low stability persist, primarily due to uneven inorganic semiconductor coverage on the COFs surface. Therefore, constructing inorganic-organic S-scheme heterojunction photocatalysts via the in-situ growth of COFs on inorganic semiconductor surfaces shows great promise. Herein, we successfully developed a sponge-like TiO2@BTTA S-scheme heterojunction with a tight contact interface by in-situ growing COF (referred to as BTTA) on the surface of sponge-like TiO2 (referred to as ST). Density Functional Theory (DFT) calculations confirmed that the ST@BTTA hybrids exhibit the optimal adsorption and desorption capabilities for H2O and H2 molecules, respectively. Notably, the ST@BTTA-120 S-scheme heterojunction photocatalyst demonstrates an outstanding hydrogen production rate under simulated sunlight irradiation, surpassing pristine ST and BTTA by factors of 10.3 and 2.6, respectively. The enhanced photocatalytic performance is attributed to improved solar energy utilization efficiency, a larger specific surface area, and an increased interfacial contact area between ST and BTTA. X-ray photoelectron spectroscopy (XPS) and electron spin resonance (ESR) analyses further verify the S-scheme carrier transfer mechanism in the ST@BTTA hybrids. This research provides a valuable method for designing efficient S-scheme heterojunction photocatalysts with closely integrated interfaces for photocatalytic hydrogen production via water splitting.

Cation vacancy-induced lattice oxygen oxidation mechanism for ultra-stable OER electrocatalysis

Catalysts adhere to the adsorbate evolution mechanism (AEM) are constrained by the linear scaling relationship between the adsorbates *OOH and *OH, leading to a theoretical overpotential of approximately 370 mV. The lattice oxygen activation mechanism (LOM) is a promising strategy for developing highly active oxygen evolution reaction (OER) electrocatalysts, but it struggles to maintain the structural stability of the catalyst. Herein, transition metal oxide catalysts (MxOy-M) enriched with metal cation vacancies (VM) have been successfully built, demonstrating the OER mechanism of metal oxides changing from AEM to LOM with outstanding structural and electrocatalytic stability. Notably, the Co3O4-M catalyst maintains stable operation as long as 240 h at high current densities of 1 A cm-2 in harsh industrial condition (30 % KOH and 85 ℃). Density functional theory (DFT) calculations reveal that the downward displacement of the d-band center of the metal in MxOy-M catalysts and the upward displacement of the O 2p band center result in increased orbital overlap, thereby augmenting the covalency of the M-O bond, which effectively facilitates the LOM reaction pathway while concurrently improving the OER stability. This study has provided a universal method for regulating the transformation of the OER mechanism and facilitated the development of new efficient lattice oxygen redox OER electrocatalysts.

Rational development of Nile red derivatives with significantly improved specificity and photostability for advanced fluorescence imaging of lipid droplets

Since the first report of Nile Red as a fluorescent probe for lipid droplets (LDs) imaging was published in 1985, this fluorescent probe has been widely used for nearly 40 years, and so far, it is still one of the most commonly used probes for LDs imaging. Although Nile Red has achieved continuous success, it has gradually emerged two major limitations (poor LDs specificity and low photostability) which directly limit the study of LDs via advanced fluorescence imaging techniques. In this context, we have developed a new synthetic route to conveniently prepare a series of Nile Red derivatives (NR-1 to NR-15). With these 15 derivatives in hand, the relationships between molecular structures and their properties (LDs specificity, photostability) have been comprehensively investigated. Consequently, we have rationally designed a new Nile Red derivative, NR-11, which exhibits significantly improved LDs specificity and photostability. Utilizing this new LDs probe, we have successfully conducted various advanced fluorescence imaging, e.g. time-lapse three-dimensional (3D) confocal imaging of cells, time-lapse 3D dynamic tracking of a single LD, and two-photon 3D imaging of tissues. These advanced imaging results not only demonstrate the utility of this new fluorescent probe but also provide novel insights into the cell biology study of LDs.

Stacked long and short-term memory (SLSTM) - assisted terahertz spectroscopy combined with permutation importance for rapid red wine varietal identification

Mislabeling of low-value red wines as high-value ones is common, which seriously undermines consumer rights and interests. However, traditional sensory and chemical analysis methods have limitations, which highlights the need for novel detection techniques. To address above issues, terahertz time-domain spectroscopy (THz-TDS) combined with deep learning (DL) was employed to distinguish different red wine varieties quickly and non-destructively, contributing to correctly identifying red wine labels. Compared with the other models, the stacked long and short-term memory (SLSTM) model based on the first derivative (1-st der) spectra performed the best (Precision: 85.72 %, Recall: 85.61 %, F1-score: 85.59 %, Accuracy: 85.61 %). In addition, feature selection (FS) was used to explore the feasibility of improving model accuracy and reducing prediction time by eliminating redundant frequencies. Compared to full frequency, the 1-st der-SLSTM model based on permutation importance (PI) performed slightly lower (Precision: 84.42 %, Recall: 84.10 %, F1-score: 84.14 %, Accuracy: 84.18 %), but the prediction time was reduced by 2 s. Therefore, different models can be selected based on different detection needs by weighing accuracy and prediction time. In conclusion, the current research demonstrates that the SLSTM-assisted THz-TDS technology provides a novel approach for fast, accurate and non-destructive for fast, accurate and non-destructive discrimination of red wine labels, facilitating the maintenance of market discipline.

Modulating nanopore size and ion transport using (Anti)-Polyelectrolyte effects inspired by the nuclear pore complex

This study explores the modulation of nanopore size and ion transport through (anti)-polyelectrolyte effects, which is inspired by the nuclear pore complex. We aimed to control ionic selectivity and rectification by applying these effects to synthetic nanopores. Single bicylindrical nanopores were fabricated on the PET membranes and functionalized with PEI/HA or PLL/PAA polyelectrolyte layers. Varying the structural and charge characteristics under different pH levels and ionic strengths revealed that at low salt concentrations, charge density and surface charge polarity significantly impacted ion selectivity and transport. At higher concentrations, conformational changes in the polyelectrolytes influenced the conductance via volume expansion or compaction. Our findings highlight the distinct roles of charge inversion and molecular expansion in nanopore transport, which can be modulated by pH and ionic environment. This work provides insights for developing highly selective ion channels with potential applications in filtration, biosensing, and nanofluidics, where precise ion transport and selective rectification are essential.

Encapsulating bimetallic nanoparticles on Mn0.3Cd0.7S solid solution for boosted photocatalytic selective imines synthesis

The synergetic combination of hydrogen (H2) generation with benzylamine (BA) dehydrogenation shows promise in terms of avoiding sacrificial agents and emitting pollutants without using up unlimited solar energy. However, the rational design of the electron transfer bridge and active sites of photocatalysts remains constrained, reducing the effectiveness of the target selective photocatalytic BA dehydrogenation coupling (PBDC) system. Herein, a bimetallic CuCo nanoparticles used as an efficient cocatalyst is coated on the Mn0.3Cd0.7S (MCS) nanorods (CuCo/MCS) that endows an optimal electronic structure, a directional electron transport tunnel, and suitable reactive sites for the PBDC reaction. Theoretical and experimental studies reveal that the synergistic effect of Cu and Co nanoparticles lowers the overall energy barrier of BA, facilitating the N-benzylidenebenzylamine (NBBA) and H2 generation. The incorporation of CuCo nanoparticles as cocatalysts into MCS not only reduces the overpotential of proton reduction but also weakens the adsorption of imine, thus producing H2 at a rate of 14.10 mmol g-1 h-1, with a BA conversion of 94.43 % and selectivity of 99 %. This work will offer a profound understanding of bimetal-anchored photocatalysts in electron transfer for synergetic renewable fuels and valuable chemical production.

Fe3+ intercalated hierarchical structured hydrated vanadate cathode for flexible iron ion hybrid supercapacitor

Energy storage devices are the core hub in constructing the modern energy system and have become an indispensable factor in driving the development of new electronic devices. In this work, we synthesized a flexible cathode of Fe3+ intercalated V2O5·3H2O (VOH) on carbon cloth (FeVOH@CC) and explored an advanced iron ion hybrid supercapacitor (IIHS). The presence of V4+/V5+ electrons in FeVOH@CC enhances the material's conductivity, while Fe3+ acts as a stabilizing pillar to accommodate structural expansion and contraction, thereby ensuring improved ion diffusion dynamics and cycling stability. Additionally, the growth of the material directly on the carbon cloth, eliminates the negative effects of conductive agents, binders, and other additives, and the prepared FeVOH@CC maintains structural flexibility, which is crucial for the effective insertion/extraction of Fe2+. As a result, the aqueous IIHS exhibits excellent areal capacitance (882.4 mF cm-2 at 1 mA cm-2) and energy density (176.5 μWh·cm-2 at 606.4 μW·cm-2). After 20,000 cycles, it retains 85.7 % of its capacity, significantly outperforming VOH. Meanwhile, we have developed a polyacrylamide/sodium alginate/glycerol-Fe2+ gel electrolyte for flexible IIHS, and the device exhibits outstanding performance by retaining 85.9 % of its capacity after 5,000 cycles. Therefore, FeVOH@CC cathode based flexible IIHS opens up new exploratory possibilities for next-generation energy storage devices.

Zirconium metal-organic cages for iodine adsorption: Effect of substituted groups and pore structures

Zirconium metal-organic cages (MOCs) have emerged as potential adsorbents for radioactive iodine absorption, one of key fission products of concern in nuclear fuel cycles. Herein a series of substituted groups functionalized Zr-MOCs were employed to investigate the influence of substituted group on iodine adsorption, in which ZrT-1-(NH2)2 showed the highest improvement on both iodine vapor and solution-based absorption. Thereafter, five longer linkers functionalized with amino groups were chosen to construct five isoreticular MOCs for iodine absorption. Among them, ZrT-2-3,3'-(NH2)2 and ZrT-3-2,2''-(NH2)2 exhibited comparable iodine vapor absorption capacity compared with ZrT-1-(NH2)2. Impressively, iodine vapor adsorption capacities (2.62 g/g and 2.50 g/g) of ZrT-1-(NH2)2 and ZrT-3-2,2''-(NH2)2, represent the second highest among all the MOCs. These five isoreticular MOCs displayed higher iodine uptake capacities via solution-based process than ZrT-1-(NH2)2. The iodine/cyclohexane uptake capacities of ZrT-2-3-NH2 and ZrT-2-3,3'-(NH2)2 and ZrT-3-2,2''-(NH2)2 are the highest among all the MOCs. Raman and XPS demonstrate the strong charge transfer from the amino-substituted linkers to absorbed iodine. Synchrotron X-ray single-crystal diffraction provides the possible iodine species distribution in the cage, clarifying the host-guest interactions between the trapped iodine and MOCs. This work may motivate the rational design of MOCs with optimized structures to enhance the adsorption properties.

Reconfigurable acoustic tweezer for precise tracking and in-situ sensing of trace miRNAs in tumor cells

MicroRNAs (miRNAs) have emerged as critical biomarkers for early cancer diagnosis and monitoring. However, their isolation from clinical samples typically yields only trace amounts, significantly limiting the sensitivity and efficiency of cancer detection. To address this challenge, we present a octangular reconfigurable acoustic tweezer (ORAT) as an integrated platform for precise tumor cell tracking and in-situ detection of trace miRNAs. By simultaneously modulating multidirectional acoustic signals and parameters, the ORAT dynamically reshapes the acoustic field, enabling precise control over manipulation areas, particle spacing, array angles, distribution patterns, and node rotation. This device allows selective particle manipulation across entire regions or specific areas through adaptive adjustments of the microchamber boundary. Notably, the ORAT achieves rapid and accurate localization and labeling of rare tumor cells within a large population of normal cells. Furthermore, it enhances the sensitivity of CRISPR/Cas-based miRNA detection in digital microdroplets by three orders of magnitude, if compared to that of the conventional tube-based method. With its versatile capabilities, the ORAT holds remarkable promise for advancing nucleic acid analysis in a wide range of cancers and related diseases.

Quantitative native speciation of ppb-level metals in semiconductor-manufacturing-used strong acids and a base

The presence of metal species in solvents significantly impacts production yields in the semiconductor industry, particularly as the dimensions of integrated circuits continue to decrease. Therefore, it is imperative to control metal concentrations in solvents to levels as low as a few parts per billion (ppb) throughout fabrication processes. Effective purification methods are essential for removing various levels of contamination, and understanding the speciation of metals is crucial for achieving efficient purification. Conventional methods for the speciation of solution-phase metals include ion chromatography (IC) and ultraviolet-visible (UV-Vis) absorption spectroscopy. However, these techniques present limitations; for instance, IC can inadvertently alter species during the elution process, while the requirement for high-purity parts per million (ppm) concentrations of metals obscures the speciation of trace mixed samples using UV-Vis absorption spectroscopy. In this study, we present a quantitative speciation method for metals in their native states within strong acids and a base, utilizing the breakthrough curve (BTC) theory in conjunction with inductively coupled plasma-mass spectrometry (ICP-MS). Sodium, potassium, magnesium, calcium, iron, and copper serve as model systems for our investigations. The combination of BTC and ICP-MS provides insights into the species present and their respective abundances. Our findings indicate that breakthrough time (tBT) is predominantly influenced by the charge states and binding selectivity of the metal species and the concentrations of competing binding species. For scenarios where the product of the adsorption equilibrium constant (K) and the concentrations of a species at equilibrium (C) is significantly less than one (KC ≪ 1), tBT serves as a critical metric for assessing metal species at trace levels. Taking sodium (I) and potassium (I) at 10 ppb as representative examples, we discovered that tBT was accelerated by a factor of 5.7 when the concentration of the competing binding species ([H]+ in this study) was increased five-fold from 0.02 M to 0.1 M nitric acid (HNO3). Specifically, the tBT for sodium (I) decreased from 23 min to 4 min, while for potassium (I), it dropped from 114 min to 20 min. Furthermore, in the cases of magnesium (II) and copper (II) at 10 ppb, tBT was expedited by a factor of approximately 25; the tBT for magnesium (II) fell from 100 min to 4 min, and for copper (II), it decreased from 157 min to 6 min when the [H]+ concentration was increased five-fold from 0.1 M to 0.5 M HNO3. Additionally, we observed distinct species transformations for iron and copper, evidenced by markedly altered tBT in 0.1 M choline hydroxide solutions, which was observed to be less than 10 min. Anionic iron complexes and neutral copper particles were inferred, supported by ion exchange and UV-Vis absorption spectroscopic measurements. Furthermore, copper particles, potentially identified as copper (II) hydroxide or copper (II) oxide, exhibited a size distribution ranging from 200 to 400 nm with a peak at 300 nm, as characterized using particle analyzers. The advantages of the BTC theory-facilitated native quantitative speciation are anticipated to enhance informed decision-making for optimizing purification processes within the semiconductor industry.

Evaluation of structure-activity relationship for nitrogen-doped carbon-based metal-free electrocatalysts using electrochemiluminescence

Nitrogen doping enhances the catalytic performance of carbon-based metal-free electrocatalysts (C-MFECs) by modifying their chemical environment. Understanding the structure-catalytic activity relationship of nitrogen-doped (N-doped) C-MFECs is crucial for elucidating catalytic mechanisms and designing efficient electrocatalysts, but it remains challenging. Recently, reactive oxygen species (ROS)-triggered electrochemiluminescence (ECL) has shown great potential for uncovering these mechanisms due to its simple setup, low background signal, wide dynamic range, and high sensitivity. In this study, four types of N-doped C-MFECs with varying nitrogen dopant types (denoted as N-Cx, where x represents the annealing temperature) towards the electrochemical reduction of H2O2 are evaluated by monitoring the cathodic ECL of the luminol-H2O2 system in the low negative-potential region. Among these, N-C900, contains a higher content of graphitic nitrogen exhibits superior catalytic performance in activating H2O2 to generate significant amounts of ROS, as evidenced by its markedly enhanced ECL emission. The increased incorporation of graphitic nitrogen into the carbon plane likely improved H2O2 adsorption and its capacity to generate ROS. A sensitive antioxidant-mediated ECL platform was successfully developed for detecting antioxidant levels in orange juice, demonstrating potential for evaluating antioxidant capacity. This study not only provides insights into the catalytic mechanisms of N-doped C-MFECs but also highlights the potential of ECL as a versatile tool for studying and designing electrocatalysts.

Dual-color and specific luminescence detection of Pd2+ ions using iridium(III) complex-based probes in food samples

The toxicity of palladium (Pd) is highly associated with its oxidative states, thus it is important to develop specific detection methods for Pd2+ ions in food and environmental systems. However, the reliable and selective detection of Pd2+ ions remains challenging. Here, we report two iridium(III) complexes with dual colors (717 nm and 637 nm) for the specific detection of Pd2+ ions, with the 3,3'-diamino group being used as a specific recognition unit for Pd2+ ions for the first time. The dual-color probes showed a luminescence quenching response to Pd2+ ions in aqueous solution within 1 min, along with an obvious color change under UV irradiation. Moreover, complexes 1-2 allow sensitive and selective detection of Pd2+ ions with a limit of detection (LOD) of 0.69 μM and 0.26 μM, respectively, showing a good linear response for Pd2+ ions in the range of 1-13 μM (R2 = 0.985) and 1-9 μM (R2 = 0.996). Finally, the probes were successfully applied for the detection of Pd2+ ions in food and environmental samples with good recoveries ranging from 85.4 to 118.7 %, providing a robust analytical tool for Pd2+ ions quantification for onsite setting.

A CRISPR/Cas13a system based on a dumbbell-shaped hairpin combined with DNA-PAINT to establish the DCP-platform for highly sensitive detection of Hantaan virus RNA

Rapid and sensitive detection of specific RNA sequences is crucial for clinical diagnosis, surveillance, and biotechnology applications. Currently, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) is the gold standard for RNA detection; however, it is associated with long processing time, complex procedures, and a high false-positive rate. To address these challenges, we developed a novel sensing platform based on CRISPR/Cas13a that incorporates a dumbbell-shaped hairpin and DNA-PAINT for rapid, highly specific, and sensitive RNA analysis. By leveraging the CRISPR/Cas13a system, this platform enables the cleavage of dumbbell-shaped hairpins, which subsequently allows the cleaved primers to initiate cyclic amplification of fluorescent signals. These signals are further enhanced by the binding and dissociation phenomena inherent to DNA-PAINT technology, ultimately achieving remarkable triple signal amplification. Additionally, the system effectively discriminates Hantaan virus RNA from Seoul virus in real samples. Importantly, the platform can be easily adapted for the detection of other RNAs by simply reconfiguring the hybridization region of crRNA. In conclusion, this platform represents a "five-in-one" RNA detection approach that integrates reliability, versatility, robustness, high specificity, and superior quantitative capabilities. It provides novel insights for direct RNA detection based on CRISPR/Cas13a and demonstrates significant potential for advancement in viral diagnostics.

Turbulence-enhanced microneedle immunoassay platform (TMIP) for high-precision biomarker detection from skin interstitial fluid

Conventional diagnostic methods for biomarker detection often require invasive procedures and exhibit limited reproducibility and sensitivity. In this study, the turbulence-enhanced microneedle immunoassay platform (TMIP) was designed to enhance the performance and accuracy of biomarker detection in skin interstitial fluid (ISF). TMIP combines a bullet-shaped microneedle (MN) array for minimally invasive biomarker capture, a microfluidic device for MN-mediated immunoassay process simplification, and a star-shaped magnetic stirrer tool (MST) to facilitate efficient washing. By targeting S100 calcium-binding protein B (S100B), a diagnostic biomarker for melanoma, TMIP demonstrated substantial improvements in reproducibility, reducing signal deviations by up to 55 % compared to manual operation. The application of nanoporous MNs (NPMNs) achieved a low detection limit of 20 pg/mL with a high linearity (R2 = 0.9758). Validation using a gelatin phantom mimicking human skin confirmed TMIP's ability to achieve improved reproducibility and sensitivity. Furthermore, TMIP successfully detected S100B with high reproducibility in both the phantom (R2 = 0.97523) and melanoma-expressing mice within a rapid incubation time of 1 min. TMIP enables the detection of biomarkers with remarkable reproducibility and sub-nanogram sensitivity by simplifying the analysis process and enhancing reagent washing through turbulence. These features suggest that TMIP has the potential to serve as an efficient and reliable tool for biomarker detection in skin ISF.

Nucleic acid-mediated SERS Biosensors: Signal enhancement strategies and applications

Surface Enhanced Raman Spectroscopy (SERS) is a powerful spectroscopic analysis technique applied in various fields due to its high selectivity, ultra-high sensitivity, and non-destructiveness. As natural biological macromolecules, nucleic acids perform a significant role in SERS biosensing. In this review, we first summarize how nucleic acids mediate the signal enhancement of SERS biosensors from three aspects: substrate self-assembly, analyte biorecognition, and molecular amplification. Among them, SERS substrates can be self-assembled by both DNA modification and coordination or electrostatic interactions. In the field of biorecognition, analyte biorecognition based on three nucleic acid recognition elements can enhance SERS signals by regulating the distance of analytes or Raman reporter molecules to the SERS substrate. In addition, nucleic acid-based enzyme and enzyme-free amplification can enhance SERS signals by enlarging the quantity of analytes or its nucleic acid intermediates. Subsequently, multidimensional applications of nucleic acid-mediated SERS signal enhancement in biomedicine, food safety, and environmental monitoring are listed. Finally, the current challenges and future exploration of nucleic acid-mediated SERS signal enhancement are discussed.

Rapid determination of amylopectin content in starch using molecular rotor fluorescent probes

This study optimized fluorescence detection conditions for CCVJ and DCVJ molecular rotors, establishing optimal excitation wavelengths (430 nm for CCVJ and 460 nm for DCVJ), probe concentrations (0.019 mM for CCVJ and 0.032 mM for DCVJ), buffer concentrations (5 mM for CCVJ and 10 mM for DCVJ), and pH values (7 for CCVJ and 4 for DCVJ), all at a detection temperature of 25 °C. These optimized conditions were then used to evaluate the efficacy of the rotors in amylopectin quantification. A linear relationship between amylopectin concentration and fluorescence intensity was observed within specific ranges. The molecular rotor methods were compared with iodine colorimetric and concanavalin A methods, demonstrating improved accuracy over iodine colorimetric method. The rotors showed sensitivity to Fe3+ and Fe2+ interference but resilience to other substances. In dilute solutions, fluorescence response was primarily influenced by starch molecular structure rather than viscosity. The CCVJ method's applicability was validated using bean samples, yielding results comparable to the concanavalin A method in accuracy and precision. This study demonstrates the potential of molecular rotors as effective tools for amylopectin quantification in both research and industrial applications.

Human serum albumin-encapsulated near-infrared hemicyanine photosensitizers for viscosity imaging and enhanced photodynamic therapy

The research successfully developed a novel dual-function near-infrared photosensitizer, CyI, which is encapsulated with human serum albumin (HSA) to form CyI-HSA nanocomplex that can simultaneously monitor the viscosity of cancer cell and enhance the efficacy of photodynamic therapy (PDT). In vitro experiments demonstrated that compared with CyI alone, CyI-HSA has superior water solubility and high photostability, and can effectively prevent aggregation-caused quenching (ACQ) caused by π-π stacking. Additionally, singlet oxygen quantum yield of CyI-HSA as high as 27.4 % under 658 nm laser irradiation, indicating significant PDT potential. Cellular experiments further revealed that CyI-HSA can monitor intracellular viscosity with high sensitivity, while generating a substantial amount of singlet oxygen, promoting PDT and cell apoptosis. Treatment of HepG-2 cells with 1 µmol/L CyI-HSA reduced cell viability by only 13 % (Laser = 100 mW cm-2). Therefore, as a kind of nano-photosensitizer integrating diagnostic and therapeutic functions, CyI-HSA has a broad prospect in the application of near-infrared hemicyanine photosensitizers in photodynamic therapy.