Synthesis of surface molecularly imprinted poly-o-phenylenediamine/TiO2/carbon nanodots with a highly enhanced selective photocatalytic degradation of pendimethalin herbicide under visible light

Target recognition and selective photocatalytic degradation of trace disinfection By-products by innovative molecular imprinting strategy

Target recognition and selective degradation of trace disinfection by-products (DBPs) in water are crucial for the safety of drinking water and surface water. However, the interference of low concentrations of chlorinated DBPs (Cl-DBPs) and other factors in water remains a major challenge. This study aims to develop a novel catalyst for targeted recognition and removal of target pollutants by constructing specific imprinting cavities (IPC) on the surface of a composite photocatalyst composed of CeO2 and biochar (BC) (CeO2@BC). As an intermediate Cl-DBPs, p-chlorophenol (4-CPs) is highly toxic, prone to bioaccumulation, and difficult to remove. Therefore, 4-CP was chosen as the representative Cl-DBPs, and the 4-CP template molecule was successfully imprinted on BC through non covalent interactions between the functional monomer methyl acrylic acid and the template molecule, which was confirmed by Fourier transform infrared and X-ray photoelectron spectroscopy analysis. The imprinted CeO2@BC (MIP-CeO2@BC) showed highly selective recognition and preferential degradation of 4-CP, with a 38 % increase (from 56 % to 94 %) in the overall removal (adsorption and photodegradation) of 4-CP than the non-imprinted precursor (CeO2@BC). In the presence of competing co-solutes, enrofloxacin (ENR, completely different molecular structure from 4-CP) or 2-chlorophenol (2-CP, has the same chemical formula as 4-CP but different substituent position of Cl), MIP-CeO2@BC removed 2.94 and 2.54 times more 4-CP in the presence of ENR or 2-CP, respectively, than CeO2@BC. This feature also enhanced the ability of the material to resist interference of dissolved organic matter in complex water matrices, with a 4-CP removal of > 60 % in the presence of high concentrations of dextrose, humic acid, or trypsin proteins. Mechanism analysis revealed that molecular imprinting (MIP) can not only selectively uptake 4-CP, but also alter the main degradation pathways, among which photo-generated electrons (e-), holes (h+), and ·OH were identified as the main active substances for degrading 4-CP. Part of the photo-generated e- can be transmitted into the IPC through BC "tunnels", activating the degradation process of 4-CPs trapped in the IPC by the active substances. The combination of MIP and active metals seemed to have the potential to improve the selectivity and effectiveness of photocatalytic degradation of Cl-DBPs in water.

Single-Template Molecularly Imprinted Chiral Sensor for Enantioselective Recognition of Various Chiral Amino Acids Based on a Dummy Template Strategy

Designing single-template molecularly imprinted chiral sensors for the enantioselective recognition of various chiral amino acids (AAs) is of great importance for chiral analysis. Here, a dummy template-based chiral sensor is developed by using l-alanine (l-Ala) as the dummy template and poly(o-phenylenediamine) as the imprinting layer, which can be used for the enantioselective recognition of various chiral AAs such as Ala, tryptophan (Trp), tyrosine (Tyr), cysteine (Cys), and arginine (Arg). Compared with conventional single-template molecularly imprinted chiral sensors, the designed single-template chiral sensor shows great universality for the recognition of chiral AAs since all chiral AAs possess an Ala-analogous segment. Also, in this work, it is found that the enantioselective recognition of different chiral AAs is greatly influenced by the sizes and isoelectric points of the AAs.

Carbon Nanodots-Based Polymer Nanocomposite: A Potential Drug Delivery Armament of Phytopharmaceuticals

Carbon nanodots (CNDs) have garnered significant attention as viable drug delivery vehicles in recent years, especially in the field of phytomedicine. Although there is much promise for therapeutic applications with phytomedicine, its effectiveness is frequently restricted by its low solubility, stability, and bioavailability. This paper offers a thorough synopsis of the developing field of phytomedicine drug delivery based on CND. It explores CND synthesis processes, surface functionalization strategies, and structural and optical characteristics. Additionally, the advantages and difficulties of phytomedicine are examined, with a focus on the contribution of drug delivery methods to the increased effectiveness of phytomedicine. The applications of CNDs in drug delivery are also included in the review, along with the mechanisms that underlie their improved drug delivery capabilities. Additionally, it looks at controlled-release methods, stability augmentation, and phytomedicine-loading tactics onto CNDs. The potential of polymeric carbon nanodots in drug delivery is also covered, along with difficulties and prospective directions going forward, such as resolving toxicity and biocompatibility issues. In summary, the present review highlights the encouraging contribution of CNDs to the field of drug delivery, specifically in enhancing the potential of phytomedicine for therapeutic purposes.

Hydrophilic molecularly imprinted lysozyme-BiOBr composite with enhanced visible light utilization for selective removal of trace contaminants in water

The development of high-efficiency molecularly imprinted photocatalysts is still challenging due to the lack of hydrophilic and suitable functional monomers. In this work, the bio-sourced lysozyme was developed as the hydrophilic functional monomer, and Cu-doped BiOBr was used as the photocatalysts, to prepare a novel hydrophilic molecularly imprinted lysozyme-BiOBr composite (BiOBr-Cu/LyzMIP) with enhanced visible light utilization. Lysozyme could form a transparent layer to mitigate the light transmission obstruction caused by the surface imprinting layer, making it an ideal functional monomer. The prepared BiOBr-Cu/LyzMIP possessed red-shifted visible-light absorption edge and minor reduction of light absorbance, indicating the enhanced utilization of visible light. Accordingly, BiOBr-Cu/LyzMIP demonstrated excellent degradation rate (99.4 % in 20 min), exceptional degradation efficiency (0.211 min-1), and superior reusability. Moreover, BiOBr-Cu/LyzMIP exhibited rapid adsorption equilibrium (20 min), good imprinting factor (2.67), and favourable degradation selectivity (>1.75), indicating the good imprinting effect resulting from abundant functional groups of lysozyme. Versatility experiments on different templates suggested that the proposed approach allowed flexibility in selecting a wide range of hazardous contaminants according to practical requirements. The present work expands the application of lysozyme-based composites in the environmental field, and provides a new one-stop pathway for efficient and sustainable treatment of contaminated water.

Application of lipid and polymeric-based nanoparticles for treatment of inner ear infections via XGBoost

Taking hearing loss as a prevalent sensory disorder, the restricted permeability of blood flow and the blood-labyrinth barrier in the inner ear pose significant challenges to transporting drugs to the inner ear tissues. The current options for hear loss consist of cochlear surgery, medication, and hearing devices. There are some restrictions to the conventional drug delivery methods to treat inner ear illnesses, however, different smart nanoparticles, including inorganic-based nanoparticles, have been presented to regulate drug administration, enhance the targeting of particular cells, and decrease systemic adverse effects. Zinc oxide nanoparticles possess distinct characteristics that facilitate accurate drug delivery, improved targeting of specific cells, and minimized systemic adverse effects. Zinc oxide nanoparticles was studied for targeted delivery and controlled release of therapeutic drugs within specific cells. XGBoost model is used on the Wideband Absorbance Immittance (WAI) measuring test after cochlear surgery. There were 90 middle ear effusion samples (ages = 1-10 years, mean = 34.9 months) had chronic middle ear effusion for four months and verified effusion for seven weeks. In this research, 400 sets underwent wideband absorbance imaging (WAI) to assess inner ear performance after surgery. Among them, 60 patients had effusion Otitis Media with Effusion (OME), while 30 ones had normal ears (control). OME ears showed significantly lower absorbance at 250, 500, and 1000 Hz than controls (p < 0.001). Absorbance thresholds >0.252 (1000 Hz) and >0.330 (2000 Hz) predicted a favorable prognosis (p < 0.05, odds ratio: 6). It means that cochlear surgery and WAI showed high function in diagnosis and treatment of inner ear infections. Regarding the R2 0.899 and RMSE 1.223, XGBoost shows excellent specificity and sensitivity for categorizing ears as having effusions absent or present or partial or complete flows present, with areas under the curve (1-0.944).

Controllable interface-tailored strategy to reduce the nanotribological properties of Ti3C2Txby depositing MoS2using atomic layer deposition

Ti3C2TxMXene has attracted widespread attention in lubrication owing to its unique structure and surface properties. However, the inferior nanotribological properties of Ti3C2Txstill limit its applications in nano lubricants. Herein, we propose a controllable interface-tailored strategy to reduce the nanotribological properties of Ti3C2Txby depositing MoS2nano-sheet on its surface using atomic layer deposition (ALD). The nanotribological properties of the MoS2/Ti3C2Txnanocomposites synthesized by ALD are studied by atomic force microscope for the first time. At the optimal 20 ALD MoS2cycles, the nanofriction of MoS2/Ti3C2Txhas been reduced by 57%, 46%, and 44% (at 5, 10, and 15 nN load, respectively), while the adhesion has been reduced by 59%, compared to the original Ti3C2Tx. The results can contribute to understanding of the nanotribological mechanisms of Ti3C2Txcomposites and provide the potential prospects for Ti3C2Txas a nanoscale adjustable lubricant.

Ba2-xHoxSr2-yNiyFe12O22 and its composite with MXene: synthesis, characterization and enhanced visible light mediated photocatalytic activity for colored dye and pesticide

The rapid recombination of charges of photogenerated electrons and holes severely limits single semiconductor photocatalytic applications. In this study, a simple and facile sol-gel approach was used to synthesize Ba2-xHoxSr2-yNiyFe12O22 (x = 0, 0.1 and y = 0, 0.5). The composite of holmium-nickel doped barium-strontium ferrite with MXene (Ba1.9Ho0.1Sr1.5Ni0.5Fe12O22@MXene) was synthesized by ultrasonication method. These synthesized samples were subsequently used to photodegrade rhodamine B (RhB) and pendimethalin under visible light illumination. The results of the experiments demonstrated that MXene, as a cocatalyst, considerably reduces the rate of recombination of charges and broadens absorption of visible light by providing increased surface functional groups to improve the photocatalytic activity of synthesized samples. MXene is thermally stable, have high electrical conductivity, have adjustable bandgap, and hydrophilic in nature. The optimized Ba1.9Ho0.1Sr1.5Ni0.5Fe12O22@MXene composite demonstrated an excellent photocatalytic rate by degrading 78.88% RhB and 75.59% pendimethalin in 140 minutes. Moreover, the scavenging experiment revealed that photogenerated electrons and holes were the primary active species involved in RhB and pendimethalin photodegradation, respectively. Ba1.9Ho0.1Sr1.5Ni0.5Fe12O22@MXene showed increased photocatalytic behavior because it has increased surface area which decreases rate of recombination of electron and hole pair, hence photocatalytic activity increases. It is observed that Ba1.9Ho0.1Sr1.5Ni0.5Fe12O22@MXene has potential application in photocatalytic degradation of harmful pollutants.

Study of the structural characteristics, optical properties, and electrical conductivity of doped [P(An-MMa)/ZrO2]TF nanofiber composite using experimental data and TD-DFT/DMol3 computations

The powder form of the new nanofiber composite of poly(acrylonitrile-co-methylmethacrylate) (P(An-MMa)) with zirconium dioxide (ZrO2) was synthesized using the sol-gel method and subsequently converted to a thin film [P(An-MMa)/ZrO2]TF via the physical vapor deposition (PVD) technique. Numerous characterization techniques, including Raman spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and ultraviolet-visible (UV-Vis) optical spectroscopy, were used to characterize [P(An-MMa)/ZrO2]TF. Additionally, using density functional theory (DFT), optimization via time-dependent density functional theory (TD-DFT/DMol3) and Cambridge Serial Total Energy Bundle (TD-DFT/CASTEP) was developed. The TD-DFT calculations accurately matched the observed XRD and Raman spectra and validated the molecular structure of the examined materials. The average crystallite size of [P(An-MMa)/ZrO2]TF, as determined by XRD calculations, is 171.04 nm. The SEM image depicts a one-dimensional morphological structure made up of tightly packed fibrous nanowires or brushes. The optical properties of the films were determined using optical absorbance spectrophotometric results in the 200-850-nm wavelength range. The optical energy bandgaps computed using Tauc's equation for [P(An-MMa)/ZrO2]TF are 2.352 and 2.253 eV, respectively, whereas the isolated molecule of the composite [P(An-MMa)/ZrO2]Iso has a bandgap of 2.415 eV as determined by TD-DFT/DMol3. The optical characteristics predicted by CASTEP in TD-DFT are in good agreement with the experimental values. The investigated large optical energy bandgap nanofiber composite is advantageous for some energy storage applications.

Ion-Selective Electrodes with Solid Contact Based on Composite Materials: A Review

Potentiometric sensors are the largest and most commonly used group of electrochemical sensors. Among them, ion-selective electrodes hold a prominent place. Since the end of the last century, their re-development has been observed, which is a consequence of the introduction of solid contact constructions, i.e., electrodes without an internal electrolyte solution. Research carried out in the field of potentiometric sensors primarily focuses on developing new variants of solid contact in order to obtain devices with better analytical parameters, and at the same time cheaper and easier to use, which has been made possible thanks to the achievements of material engineering. This paper presents an overview of new materials used as a solid contact in ion-selective electrodes over the past several years. These are primarily composite and hybrid materials that are a combination of carbon nanomaterials and polymers, as well as those obtained from carbon and polymer nanomaterials in combination with others, such as metal nanoparticles, metal oxides, ionic liquids and many others. Composite materials often have better mechanical, thermal, electrical, optical and chemical properties than the original components. With regard to their use in the construction of ion-selective electrodes, it is particularly important to increase the capacitance and surface area of the material, which makes them more effective in the process of charge transfer between the polymer membrane and the substrate material. This allows to obtain sensors with better analytical and operational parameters. Brief characteristics of electrodes with solid contact, their advantages and disadvantages, as well as research methods used to assess their parameters and analytical usefulness were presented. The work was divided into chapters according to the type of composite material, while the data in the table were arranged according to the type of ion. Selected basic analytical parameters of the obtained electrodes have been collected and summarized in order to better illustrate and compare the achievements that have been described till now in this field of analytical chemistry, which is potentiometry. This comprehensive review is a compendium of knowledge in the research area of functional composite materials and state-of-the-art SC-ISE construction technologies.

Calf thymus ds-DNA intercalation with pendimethalin herbicide at the surface of ZIF-8/Co/rGO/C3N4/ds-DNA/SPCE; A bio-sensing approach for pendimethalin quantification confirmed by molecular docking study

Pendimethalin (PND) is a herbicide that is regarded to be possibly carcinogenic to humans and toxic to the environment. Herein, we fabricated a highly sensitive DNA biosensor based on ZIF-8/Co/rGO/C₃N₄ nanohybrid modification of a screen-printed carbon electrode (SPCE) to monitor PND in real samples. The layer-by-layer fabrication pathway was conducted to construct ZIF-8/Co/rGO/C₃N₄/ds-DNA/SPCE biosensor. The physicochemical characterization techniques confirmed the successful synthesis of ZIF-8/Co/rGO/C₃N₄ hybrid nanocomposite, as well as the appropriate modification of the SPCE surface. The utilization of ZIF-8/Co/rGO/C₃N₄ nanohybrid as a modifier was analyzed using. The electrochemical impedance spectroscopy results showed that the modified SPCE exhibited significantly lowered charge transfer resistance due to the enhancement of its electrical conductivity and facilitation of the transfer of charged particles. The proposed biosensor successfully quantified PND in a wide concentration range of 0.01-35 μM, with a limit of detection (LOD) value of 8.0 nM. The PND monitoring capability of the fabricated biosensor in real samples including rice, wheat, tap, and river water samples was verified with a recovery range of 98.2-105.6%. Moreover, to predict the interaction sites of PND herbicide with DNA, the molecular docking study was performed between the PND molecule and two sequence DNA fragments and confirmed the experimental findings. This research sets the stage for developing highly sensitive DNA biosensors that will be used to monitor and quantify toxic herbicides in real samples by fusing the advantages of nanohybrid structures with crucial knowledge from a molecular docking investigation.

Nanofriction Properties of Mono- and Double-Layer Ti3C2Tx MXenes

Unique structure and ability to control the surface termination groups of MXenes make these materials extremely promising for solid lubrication applications. Due to the challenging delamination process, the tribological properties of two-dimensional MXenes particles have been mostly investigated as additive components in the solvents working in the macrosystem, while the understanding of the nanotribological properties of mono- and few-layer MXenes is still limited. Here, we investigate the nanotribological properties of mono- and double-layer Ti₃C₂T_x MXenes deposited by the Langmuir-Schaefer technique on SiO₂/Si substrates. The friction of all of the samples demonstrated superior lubrication properties with respect to SiO₂ substrate, while the friction force of the monolayers was found to be slightly higher compared to double- and three-layer flakes, which demonstrated similar friction. The coefficient of friction was estimated to be 0.087 ± 0.002 and 0.082 ± 0.003 for mono- and double-layer flakes, respectively. The viscous regime was suggested as the dominant friction mechanism at high scanning velocities, while the meniscus forces affected by contamination of the MXenes surface were proposed to control the friction at low sliding velocities.

Role of polyaniline in accomplishing a sustainable environment: recent trends in polyaniline for eradicating hazardous pollutants

Attaining a sustainable environment has become a prime area of research interest, as it is an utmost necessity for a healthy life. Hence, ample studies have been carried out in adopting different processes and utilizing various materials to attain the goal. Herein, we present an exclusive discussion on one such material, i.e., polyaniline (PANI) and its derivatives. Being an intrinsic conducting type, it has grabbed more attention due to its durability in different doped/un-doped states, promptness in structural alteration, and solution processability. This review presents an exhaustive discussion on published reports showing utilization of PANI and its derivative in various forms like pure and composites, for cleaning the environment through adsorption, photodegradation, etc., and the various methods adopted in order to achieve an optimum operating condition to obtain the maximum outcome. In addition to these merits and demerits, various technical challenges faced with materials have been also presented. Therefore, it is expected that this piece of work, presenting the exhaustive discussion on PANI and; its derivatives would help to develop a better understanding of this excellent conducting polymer PANI and provide a state of art on the role of this material for attaining sustainable surroundings for the living beings.

Degradation of toxic agrochemicals and pharmaceutical pollutants: Effective and alternative approaches toward photocatalysis

Emerging concern regarding the remediation of environmental pollution has expanded tremendously in recent years. Pharmaceutical industries and agricultural sectors release an enormous amount of residues containing toxic pollutants at trace levels which poses a serious impact on the environment and human health. To cope with the effect of hazardous and toxic contaminants, numerous methodologies have been developed for the treatment of effluents released from the agrochemical and pharmaceutical industries. Amongst them, photocatalysis has gained much more attention for the degradation of pollutants due to its low cost, higher capability, green and eco-friendly approaches. Photocatalysts are the substrate that plays a key role in pollutant removal through photocatalysis by accelerating the necessary chemical reactions using a light source. In this review, the recent progress on photocatalysis and its fundamental mechanism in agrochemicals and pharmaceutical pollutant degradation was summarized. This review concisely discusses the incorporation of various metal oxides and nanomaterials into semiconductors for the effective degradation of contaminants. The current status and future research on different sectors and the difficulties in the photocatalytic removal of agrochemical and pharmaceutical pollutants are also reviewed in detail.

Design and Preparation of Biomass-Derived Activated Carbon Loaded TiO2 Photocatalyst for Photocatalytic Degradation of Reactive Red 120 and Ofloxacin

The design and development of novel photocatalysts for treating toxic substances such as industrial waste, dyes, pesticides, and pharmaceutical wastes remain a challenging task even today. To this end, a biowaste pistachio-shell-derived activated carbon (AC) loaded TiO2 (AC-TiO2) nanocomposite was fabricated and effectively utilized towards the photocatalytic degradation of toxic azo dye Reactive Red 120 (RR 120) and ofloxacin (OFL) under UV-A light. The synthesized materials were characterized for their structural and surface morphology features through various spectroscopic and microscopic techniques, including high-resolution transmission electron microscope (HR-TEM), field emission scanning electron microscope (FE-SEM) along with energy dispersive spectra (EDS), diffuse reflectance spectra (DRS), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, photoluminescence spectra (PL) and BET surface area measurements. AC-TiO2 shows enhanced photocatalytic activity compared to bare TiO2 due to the change in the bandgap energy and effective charge separation. The degradation rate of dyes was affected by the bandgap of the semiconductor, which was the result of the deposition weight percentage of AC onto the TiO2. The presence of AC influences the photocatalytic activity of AC-TiO2 composite towards RR 120 and OFL degradation. The presence of heteroatoms-enriched AC enhances the charge mobility and suppresses the electron-hole recombination in AC-TiO2 composite, which enhances the photocatalytic activity of the composite. The hybrid material AC-TiO2 composite displayed a higher photocatalytic activity against Reactive Red 120 and ofloxacin. The stability of the AC-TiO2 was tested against RR 120 dye degradation with multiple runs. GC-MS analyzed the degradation intermediates, and a suitable degradation pathway was also proposed. These results demonstrate that AC-TiO2 composite could be effectively used as an ecofriendly, cost-effective, stable, and highly efficient photocatalyst.

Visible-Light-Driven Carbon-Doped TiO2-Based Nanocatalysts for Enhanced Activity toward Microbes and Removal of Dye

Solar-driven photocatalytic approach is an attractive, clean, and effective way for decontamination of water. In this work, visible-light-activated TiO₂ nanoflakes (TNFs) and carbon-doped TiO₂ nanoflakes (C-TNFs) were synthesized via a facile hydrothermal route using different carbon sources. The as-synthesized nanostructures were successfully characterized by powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM), critically disclosing the anatase nature containing titanium-oxygen having flake/platelet-like morphology with ∼32 nm in size, respectively. The photocatalytic activity was characterized via the degradation of methylene blue (MB) and bacterial inactivation of Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive). The experimental results showed that C-TNFs significantly enhanced photocatalytic activity compared to bare TNFs. It was found that TNF nanocatalysts exhibited superior photocatalytic activity against photodegradation of MB (92.7%) and antibacterial activity (85.6%) under sunlight irradiation. In addition, reduced graphene oxide (RGO)-TNFs have a good recycling ability and are expected to be a promising candidate for photocatalytic applications under sunlight. Consequentially, the higher activity of RGO-TNF nanocatalysts under sunlight irradiation for organic degradation and bacterial inactivation implies that hydrothermal synthesis allows for the preparation of efficient and low-cost carbon-doped photocatalysts for the photodegradation of a wide range of environmental pollutants.

Preparation of molecularly imprinted Ag-TiO2 for photocatalytic removal of ethyl paraben

Herein, MI-Ag-TiO2 was prepared by one-step sol-gel method, and its photocatalytic and characterization performance were fully analyzed. Within 120 min, the photocatalytic degradation rate of MI-Ag-TiO2 to ethyl paraben was 93.4%, which was 1.48 times that of naked TiO2. Compared with Ag-TiO2, MI-TiO2, and TiO2, the photocatalytic selectivity of MI-Ag-TiO2 to target pollutants increased by 24.5%, 31.5%, and 100%, respectively. Hence, the one-step molecular imprinting method can simply and quickly improve the photocatalytic performance of TiO2. This research may help to further promote the practical application of molecularly imprinted photocatalysts in the future.

Targeted degradation of refractory organic compounds in wastewaters based on molecular imprinting catalysts

Efficient removal of low-concentration refractory pollutants is a crucial problem to ensuring water safety. The use of heterogeneous catalysis of molecular imprinting technology combined with traditional catalysts is a promising method to improve removal efficiency. Presently, the research into molecular imprinting targeting catalysts focuses mainly on material preparation and performance optimization. However, more researchers are investigating other applications of imprinting materials. This review provides recent progress in photocatalyst preparation, electrocatalyst, and Fenton-like catalysts synthesized by molecular imprinting. The principle and control points of target catalysts prepared by precipitation polymerization (PP) and surface molecular imprinting (S-MIP) are introduced. Also, the application of imprinted catalysts in targeted degradation of drugs, pesticides, environmental hormones, and other refractory pollutants is summarized. In addition, the reusability and stability of imprinted catalyst in water treatment are discussed, and the possible ecotoxicity risk is analyzed. Finally, we appraised the prospects, challenges, and opportunities of imprinted catalysts in the advanced oxidation process. This paper provides a reference for the targeted degradation of refractory pollutants and the preparation of targeted catalysts.

A photoelectrochemical sensor based on Z-Scheme TiO2@Au@CdS and molecularly imprinted polymer for uric acid detection

A novel photoelectrochemical (PEC) sensor based on "Z-scheme" TiO₂@Au@CdS and molecularly imprinted polymer (MIP) was developed for the non-invasive detection of uric acid (UA). The "Z-scheme" material, consisting of an electron-transfer system (Au) and two isolated photochemical systems (CdS, TiO₂), was synthesized by chemical deposition method and it worked as a substrate for electro-polymerization of MIP. Due to the high photoelectric conversion efficiency provided by TiO₂@Au@CdS and specific imprinting effect afforded by MIP, the sensor displayed desirable sensing performance with the merits of sensitivity, selectivity, repeatability, and stability. The linear range for UA detection is from 1 nM to 9 μM with the detection limit of 0.3 nM (S/N = 3). Moreover, the assay was successfully utilized to measure UA in human tears and offered a reliable result. The incorporation of MIP and "Z-scheme" material into a PEC sensor system is expected to provide a promising strategy for detecting other small molecules.

Innovative utilization of molecular imprinting technology for selective adsorption and (photo)catalytic eradication of organic pollutants

The rapid development of industrialization and urbanization results in a numerous production of various organic chemicals to meet the increasing demand in high-quality life. During the synthesis and utilization of these chemical products, their residues unavoidably emerged in environments to severely threaten human's health. It is thus urgent to exploit effective technology for readily removing the organic pollutants with high selectivity and good reusability. As one of the most promising approaches, molecular imprinting technology (MIT) employs a chemically synthetic route to construct artificial recognition sites in highly-crosslinked matrix with complementary cavity and functional groups to target species, which have been attracting more and more interest for environmental remediation, such as the selective adsorption/separation and improved catalytic degradation of pollutants. In this review, MIT is first introduced briefly to understand their preparing process, recognition mechanism and common imprinted systems. Then, their specific binding affinities are demonstrated for selectively adsorbing and removing target molecules with a large capacity. Furthermore, the innovative utilization of MIT in catalytic eradication of pollutants is comprehensively overviewed to emphasize their enhanced efficiency and improved performances, which are classified by the used catalytically-active nanocrystals and imprinted systems. After summarizing recent advances in these fields, some limitations are discussed and possible suggestions are given to guide the future exploitation on MIT for environmental protection.

Recent Advances in Synthesis and Applications of Carbon-Doped TiO2 Nanomaterials

TiO2 has been widely used as a photocatalyst and an electrode material toward the photodegradation of organic pollutants and electrochemical applications, respectively. However, the properties of TiO2 are not enough up to meet practical needs because of its intrinsic disadvantages such as a wide bandgap and low conductivity. Incorporation of carbon into the TiO2 lattice is a promising tool to overcome these limitations because carbon has metal-like conductivity, high separation efficiency of photogenerated electron/hole pairs, and strong visible-light absorption. This review would describe and discuss a variety of strategies to develop carbon-doped TiO2 with enhanced photoelectrochemical performances in environmental, energy, and catalytic fields. Emphasis is given to highlight current techniques and recent progress in C-doped TiO2-based materials. Meanwhile, how to tackle the challenges we are currently facing is also discussed. This understanding will allow the process to continue to evolve and provide facile and feasible techniques for the design and development of carbon-doped TiO2 materials.