A conjugated microporous polymer based visual sensing platform for aminoglycoside antibiotics in water

Fully Conjugated Microporous Polymers as Metal-Free Heterogeneous Photocatalysts for Organic Transformations

Photoactive conjugated microporous polymers (CMPs) have recently received huge attention in photocatalytic organic transformations owing to their adjustable structure and functionality. However, commonly reported CMPs are synthesized through metal catalyzed coupling reactions, which require complicated product separation and result in increased costs. In this study, two sp2 carbon-linked CMPs are constructed by organic base induced Knoevenagel reaction using 2,6-dimethylbenzo[1,2-d:4,5-d']bisoxazole and aromatic polyaldehydes as co-monomers. The new benzobisoxazole-based polymer materials feature fully π-conjugated skeleton with broad visible-light absorption, permanent porosity as well as outstanding stability. Importantly, they can effectively induce many organic reactions such as C-3 thiocyanation of indoles under visible-light illumination and show broad substrate applicability and superior recyclability.

Assessing interactions between antibiotics and triazine porous organic polymeric sorbents by photophysics

This study purposes three triazine-based porous organic polymers (T-POPs 1-3) as advanced platforms for the early detection of antibiotic-polluted environments and effective water decontamination, in order to mitigate water pollution and antimicrobial resistance, which are two huge current problems damaging ecosystems and human health. T-POPs exhibited good performances as adsorbents for the removal of sulfamethazine (SMT) and tetracycline (TC) from water, with efficiencies up to 97% and 96%, and maximum adsorption capacities between (0.36-0.44) and (0.21-0.27) mmol g-1, respectively, which are similar or even higher (up to 40.3 times) than those reported for other materials. In addition, good reusability was achieved, particularly for T-POP2, despite being the polymer with the lowest surface area. A slightly higher selectivity of T-POPs for sulfonamides and the best performance of T-POP3 to remove six antibiotics from a micromolar solution were observed. T-POPs also acted as fluorescent chemosensors, since T-POP1 underwent linear Stern-Volmer fluorescence quenching in the presence of both SMT and TC, while the enhanced-fluorescent T-POP2 and T-POP3 experienced fluorescence extinction through a sphere of action mechanism in contact with TC, and bathochromic shift accompanied by a hyperchromic effect on the new fluorescent region with the increase in SMT concentration. Thus, T-POP2 and T-POP3 can both promote a selective on-site monitoring of each drug in contaminated water streams and an efficient water remediation, thanks to the synergy between hydrogen and van der Waals interactions. In summary, these triazine-based porous organic polymers are promising materials for the simultaneous monitoring and treatment of antibiotic-containing water and wastewaters.

Macromolecular Architecture in the Synthesis of Micro- and Mesoporous Polymers

Polymers with micro- and mesoporous structure are promising as materials for gas storage and separation, encapsulating agents for controlled drug release, carriers for catalysts and sensors, precursors of nanostructured carbon materials, carriers for biomolecular immobilization and cellular scaffolds, as materials with a low dielectric constant, filtering/separating membranes, proton exchange membranes, templates for replicating structures, and as electrode materials for energy storage. Sol-gel technologies, track etching, and template synthesis are used for their production, including in micelles of surfactants and microemulsions and sublimation drying. The listed methods make it possible to obtain pores with variable shapes and sizes of 5-50 nm and achieve a narrow pore size distribution. However, all these methods are technologically multi-stage and require the use of consumables. This paper presents a review of the use of macromolecular architecture in the synthesis of micro- and mesoporous polymers with extremely high surface area and hierarchical porous polymers. The synthesis of porous polymer frameworks with individual functional capabilities, the required chemical structure, and pore surface sizes is based on the unique possibilities of developing the architecture of the polymer matrix.

Chromatic covalent organic frameworks enabling in-vivo chemical tomography

Covalent organic frameworks designed as chromatic sensors offer opportunities to probe biological interfaces, particularly when combined with biocompatible matrices. Particularly compelling is the prospect of chemical tomography - or the 3D spatial mapping of chemical detail within the complex environment of living systems. Herein, we demonstrate a chromic Covalent Organic Framework (COF) integrated within silk fibroin (SF) microneedles that probe plant vasculature, sense the alkalization of vascular fluid as a biomarker for drought stress, and provide a 3D in-vivo mapping of chemical gradients using smartphone technology. A series of Schiff base COFs with tunable pKa ranging from 5.6 to 7.6 enable conical, optically transparent SF microneedles with COF coatings of 120 to 950 nm to probe vascular fluid and the surrounding tissues of tobacco and tomato plants. The conical design allows for 3D mapping of the chemical environment (such as pH) at standoff distances from the plant, enabling in-vivo chemical tomography. Chromatic COF sensors of this type will enable multidimensional chemical mapping of previously inaccessible and complex environments.

Conjugated microporous polymer for solid-phase extraction of neonicotinoid insecticides from environmental water samples

Conjugated microporous polymers (CMPs) have unique characteristics and have been used in a range of fascinating applications in separation sciences. In this study, a CMP, designated as CMP-1, was synthesized via the Sonogashira-Hagihara coupling reaction using 1,3,5-triphenylbenzene and 1,4-dibromobenzene as building blocks. CMP-1 features a large surface area, abundant micropore structures, and excellent stability, making it a promising solid-phase extraction adsorbent for the efficient enrichment of neonicotinoid insecticides (NEOs). Under the optimized conditions, CMP-1 was combined with high-performance liquid chromatography and diode array detection to enable the detection of NEOs with a wide linear range (0.5-200 μg·L-1), a low detection limit (0.26-0.58 μg·L-1), and acceptable precision. The developed method was applied to determine spiked NEOs in three types of environmental water samples, with recoveries of 73.7%-112.0% and relative standard deviations of 0.6%-9.4%.

Powders to Thin Films: Advances in Conjugated Microporous Polymer Chemical Sensors

Chemical sensing of harmful species released either from natural or anthropogenic activities is critical to ensuring human safety and health. Over the last decade, conjugated microporous polymers (CMPs) have been proven to be potential sensor materials with the possibility of realizing sensing devices for practical applications. CMPs found to be unique among other porous materials such as metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) due to their high chemical/thermal stability, high surface area, microporosity, efficient host-guest interactions with the analyte, efficient exciton migration along the π-conjugated chains, and tailorable structure to target specific analytes. Several CMP-based optical, electrochemical, colorimetric, and ratiometric sensors with excellent selectivity and sensing performance were reported. This review comprehensively discusses the advances in CMP chemical sensors (powders and thin films) in the detection of nitroaromatic explosives, chemical warfare agents, anions, metal ions, biomolecules, iodine, and volatile organic compounds (VOCs), with simultaneous delineation of design strategy principles guiding the selectivity and sensitivity of CMP. Preceding this, various photophysical mechanisms responsible for chemical sensing are discussed in detail for convenience. Finally, future challenges to be addressed in the field of CMP chemical sensors are discussed.

Molecular imprinting technology for biomedical applications

Molecularly imprinted polymers (MIPs), a type of biomimetic material, have attracted considerable interest owing to their cost-effectiveness, good physiochemical stability, favourable specificity and selectivity for target analytes, and widely used for various biological applications. It was demonstrated that MIPs with significant selectivity towards protein-based targets could be applied in medicine, diagnostics, proteomics, environmental analysis, sensors, various in vivo and/or in vitro applications, drug delivery systems, etc. This review provides an overview of MIPs dedicated to biomedical applications and insights into perspectives on the application of MIPs in newly emerging areas of biotechnology. Many different protocols applied for the synthesis of MIPs are overviewed in this review. The templates used for molecular imprinting vary from the minor glycosylated glycan-based structures, amino acids, and proteins to whole bacteria, which are also overviewed in this review. Economic, environmental, rapid preparation, stability, and reproducibility have been highlighted as significant advantages of MIPs. Particularly, some specialized MIPs, in addition to molecular recognition properties, can have high catalytic activity, which in some cases could be compared with other bio-catalytic systems. Therefore, such MIPs belong to the class of so-called 'artificial enzymes'. The discussion provided in this manuscript furnishes a comparative analysis of different approaches developed, underlining their relative advantages and disadvantages highlighting trends and possible future directions of MIP technology.

A Stimuli-Responsive Dual-Emitting Covalent Organic Framework Shows Selective Sensing of Highly Corrosive Acidic Media via Fluorescence Turn-On Signal with White Light Emission

Luminescent covalent organic frameworks (LCOFs) have been employed as platforms for sensing analytes. Judicial incorporation of appropriate functional units inside the framework leads to the different electronic states in the presence of external stimuli, e.g., temperature, pH, etc. We report herein a new COF (TPEPy) as a solid-state acid sensor specific for the highly acidic environments that range from pH ∼0.5 to ∼3.0. This COF shows a protonation-induced reversible color change from bright yellow to deep red upon decreasing the pH from 3 to 0.5 and vice versa. No visual color change was, however, observed above pH 3.0. Photoluminescence (PL) studies show that the intrinsic emission peak of the TPEPy COF at 530 nm is shifted to 420 nm owing to the N-protonation of the imine nitrogen of COF within this pH range. Extensive studies demonstrate that the protonation behavior of the COF is counterion dependent. This was revealed when different acids, e.g., HCl, HNO3, HBr, and HI, were employed. The intensity of the proton-induced emission peak at 420 nm depends significantly upon the counterions with the order of HCl > HNO3 > HBr > HI. These anions interact with the protonated TPEPy COF by cation-anion and H-bonding interactions. Further, the pristine COF showed near white light emission at a particular pH of 2.5 (CIE coordinates 0.27, 0.32). From the PL spectrophotometric titrations, the deprotonation pKa was experimentally found to be 1.8 ± 0.02 for the TPEPy COF. The sensor reported herein is reversible, reusable, and regenerable and is useful for assessing pH fluctuations within a strongly acidic range via digital signaling.

Porphyrin/phthalocyanine-based porous organic polymers for pollutant removal and detection: Synthesis, mechanisms, and challenges

The growing global concern about environmental threats due to environmental pollution requires the development of environmentally friendly and efficient removal/detection materials and methods. Porphyrin/phthalocyanine (Por/Pc) based porous organic polymers (POPs) as a newly emerging porous material are prepared through polymerizing building blocks with different structures. Benefiting from the high porosity, adjustable pore structure, and enzyme-like activities, the Por/Pc-POPs can be the ideal platform to study the removal and detection of pollutants. However, a systematic summary of their application in environmental treatment is still lacking to date. In this review, the development of various Por/Pc-POPs for pollutant removal and detection applications over the past decade was systematically addressed for the first time to offer valuable guidance on environmental remediation through the utilization of Por/Pc-POPs. This review is divided into two sections (pollutants removal and detection) focusing on Por/Pc-POPs for organic, inorganic, and gaseous pollutants adsorption, photodegradation, and chemosensing, respectively. The related removal and sensing mechanisms are also discussed, and the methods to improve removal and detection efficiency and selectivity are also summarized. For the future practical application of Por/Pc-POPs, this review provides the emerging research directions and their application possibility and challenges in the removal and detection of pollutants.

Amorphous porous organic polymers containing main group elements

Amorphous porous organic polymers (aPOPs) are a type of highly crosslinked polymers. These polymers are generally constructed from rigid organic building blocks, which have become an important subclass of POPs with diverse applications. In the early stage of development, a wide range of carbon-based building blocks and network forming chemistry afforded a large library of aPOPs with rich structures and properties. Recently, implanting main group elements with diverse geometric structures and electronic configurations into aPOPs has proven to be a useful tool to fine-tune the structures and properties of these polymers. Herein, we outline the recent advances in the field of main group (MG)-aPOPs where main-group elements either played unique roles in tuning the structures and properties of MG-aPOPs, or offered new strategies in the synthesis of MG-aPOPs. Furthermore, this Review discusses various challenges remaining in the field from the perspectives of synthetic strategies and characterization techniques, and presents some specific studies that may potentially address the challenges.

Composite porphyrin-based conjugated microporous polymer/graphene oxide capable of photo-triggered combinational antibacterial therapy and wound healing

Developing antibiotic-free treatment strategies to cope with the crisis on drug-resistant bacteria, are urgently needed. Antibiotics-independent physical approaches, especially the non-invasive phototherapies, worked through the assistance of photosensitizer (PS), have geared intensive attention and interests. Here, composite porphyrin-based conjugated microporous polymer/graphene oxide, denoted as GO-TAPP, combining the advantages of each component perfectly, was developed as broad-spectrum antibacterial agent. GO-TAPP, prepared via the self-oxidation coupling of tetraethynyl porphyrin on the surface of graphene oxide, could exert synergistic photothermal (PTT, ascribed to the graphene) and photodynamic (PDT, derived from the Porphyrin polymer) antimicrobial effectiveness. Both the in vivo and in vitro experiments have confirmed GO-TAPP are extremely potent against the Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) pathogens, which presents a remarkably enhanced sterilizing effect in comparison with its counterparts (the bare GO, and TAPP). Meanwhile, the synergistic effect of GO-TAPP could significantly accelerate the healing of open wound infected by bacterial. Altogether, this work proposed a new approach for the rational preparation of highly biocompatible graphene-based composite materials as antibiotic-free agents with synergistic antibacterial effect to combat bacterial infections.

The syntheses of fluorescein-based conjugated microporous polymers by direct arylation polymerization and fluorescence sensing Fe3+ in aqueous solutions

Determination of ferri ions in environment and human bodies is very important for environmental protection and disease diagnosis. Recently, conjugated microporous polymers (CMPs) used for fluorescence sensing metal ions have attracted much attention, but this technique is done in organic solvents. In this study, the two new fluorescein-based CMPs named FLEDOT and FLBTh were synthesized by "greener method", direct arylation polymerization, with tetraiodofluorescein sodium salt (TIFS) and 3,4-ethylenedioxy thiophene or 2,2'-bithiophene. Pleasely, the prepared fluorescein-based CMPs can fluorescently sense for Fe3+ in water with high sensitivity and selectivity. The quenching constants (KSV) of FLEDOT and FLBTh are 1.51 × 104 and 1.09 × 104 L mol-1, and the limits of detection (LODs) as low as 1.99 × 10-10 and 2.75 × 10-10 mol L-1, which are comparable to the sensitivity found in organic solvents' dispersions such as N,N-dimethylformamide (DMF)' dispersions. UV-Vis absorption spectra show that the fluorescence quenching mechanisms of Fe3+ are absorption competition quenching process and energy transfer process.

Porous organic polymers (POPs) for environmental remediation

Modern global industrialization along with the ever-increasing growth of the population has resulted in continuous enhancement in the discharge and accumulation of various toxic and hazardous chemicals in the environment. These harmful pollutants, including toxic gases, inorganic heavy metal ions, anthropogenic waste, persistent organic pollutants, toxic dyes, pharmaceuticals, volatile organic compounds, etc., are destroying the ecological balance of the environment. Therefore, systematic monitoring and effective remediation of these toxic pollutants either by adsorptive removal or by catalytic degradation are of great significance. From this viewpoint, porous organic polymers (POPs), being two- or three-dimensional polymeric materials, constructed from small organic molecules connected with rigid covalent bonds have come forth as a promising platform toward various leading applications, especially for efficient environmental remediation. Their unique chemical and structural features including high stability, tunable pore functionalization, and large surface area have boosted the transformation of POPs into various macro-physical forms such as thick and thin-film membranes, which led to a new direction in advanced level pollutant removal, separation and catalytic degradation. In this review, our focus is to highlight the recent progress and achievements in the strategic design, synthesis, architectural-engineering and applications of POPs and their composite materials toward environmental remediation. Several strategies to improve the adsorption efficiency and catalytic degradation performance along with the in-depth interaction mechanism of POP-based materials have been systematically summarized. In addition, evolution of POPs from regular powder form application to rapid and more efficient size and chemo-selective, "real-time" applicable membrane-based application has been further highlighted. Finally, we put forward our perspective on the challenges and opportunities of these materials toward real-world implementation and future prospects in next generation remediation technology.

Construction of Ultrastable Conjugated Microporous Polymers Containing Thiophene and Fluorene for Metal Ion Sensing and Energy Storage

In this study, we have used the one-pot polycondensation method to prepare novel 2D conjugated microporous polymers (Th-F-CMP) containing thiophene (Th) and fluorene (Fl) moieties through the Suzuki cross-coupling reaction. The thermogravimetric analysis (TGA) data revealed that Th-F-CMP (T_d10 = 418 °C, char yield: 53 wt%). Based on BET analyses, the Th-F-CMP sample displayed a BET specific surface area of 30 m² g^-1, and the pore size was 2.61 nm. Next, to show the effectiveness of our study, we utilized Th-F-CMP as a fluorescence probe for the selective detection of Fe³⁺ ions at neutral pH with a linear range from 2.0 to 25.0 nM (R² = 0.9349). Furthermore, the electrochemical experimental studies showed that the Th-F-CMP framework had a superior specific capacity of 84.7 F g^-1 at a current density of 0.5 A g^-1 and outstanding capacitance retention (88%) over 2000 cycles.

Efficacious and sustained release of an anticancer drug mitoxantrone from new covalent organic frameworks using protein corona

Solid porous and crystalline covalent organic frameworks (COFs) are characterized by their higher specific BET surface areas and functional pore walls, which allow the adsorption of various bioactive molecules inside the porous lattices. We have introduced a perylene-based COF, PER@PDA-COF-1, which acts as an effective porous volumetric reservoir for an anticancer drug, mitoxantrone (MXT). The drug-loaded COF (MXT-PER@PDA-COF-1) exhibited zero cellular release of MXT towards cancer cells, which can be attributed to the strong intercalation between the anthracene-dione motif of the drug and the perylene-based COF backbone. Here, we have introduced a strategy involving the serum-albumin-triggered intracellular release of mitoxantrone from MXT-PER@PDA-COF-1. The serum albumin acts as an exfoliating agent and as a colloidal stabilizer in PBS medium (pH = 7.4), rapidly forming a protein corona around the exfoliated COF crystallites and inducing the sustained release of MXT from the COF into tumorigenic cells.

Development of molecularly imprinted polymer based phase boundaries for sensors design (review)

Achievements in polymer chemistry enables to design artificial phase boundaries modified by imprints of selected molecules and some larger structures. These structures seem very useful for the design of new materials suitable for affinity chromatography and sensors. In this review, we are overviewing the synthesis of molecularly imprinted polymers (MIPs) and the applicability of these MIPs in the design of affinity sensors. Such MIP-based layers or particles can be used as analyte-recognizing parts for sensors and in some cases they can replace very expensive compounds (e.g.: antibodies, receptors etc.), which are recognizing analyte. Many different polymers can be used for the formation of MIPs, but conducing polymers shows the most attractive capabilities for molecular-imprinting by various chemical compounds. Therefore, the application of conducting polymers (e.g.: polypyrrole, polyaniline, polythiophene, poly(3,4-ethylenedioxythiophene), and ortho-phenylenediamine) seems very promising. Polypyrrole is one of the most suitable for the development of MIP-based structures with molecular imprints by analytes of various molecular weights. Overoxiation of polypyrrole enables to increase the selectivity of polypyrrole-based MIPs. Methods used for the synthesis of conducting polymer based MIPs are overviewed. Some methods, which are applied for the transduction of analytical signal, are discussed, and challenges and new trends in MIP-technology are foreseen.

Porous organic polymers as a platform for sensing applications

Sensing analysis is significantly important for human health and environmental safety, and has gained increasing concern. As a promising material, porous organic polymers (POPs) have drawn widespread attention due to the availability of plentiful building blocks and their tunable structures, porosity and functions. Moreover, the permanent porous nature could provide a micro-environment to interact with guest molecules, rendering POPs attractive for application in the sensing field. In this review, we give a comprehensive overview of POPs as a platform for sensing applications. POP-based sensors are mainly divided into five categories, including fluorescence turn-on sensors, fluorescence turn-off sensors, ratiometric fluorescent sensors, colorimetric sensors and chemiresistive sensors, and their various sensing applications in detecting explosives, metal ions, anions, small molecules, biological molecules, pH changes, enantiomers, latent fingerprints and thermosensation are summarized. The different structure-based POPs and their corresponding synthetic strategies as well as the related sensing mechanisms mainly including energy transfer, donor-acceptor electron transfer, absorption competition quenching and inner filter effect are also involved in the discussion. Finally, the future outlook and perspective are addressed briefly.

Electrochemically Deposited Molecularly Imprinted Polymer-Based Sensors

This review is dedicated to the development of molecularly imprinted polymers (MIPs) and the application of MIPs in sensor design. MIP-based biological recognition parts can replace receptors or antibodies, which are rather expensive. Conducting polymers show unique properties that are applicable in sensor design. Therefore, MIP-based conducting polymers, including polypyrrole, polythiophene, poly(3,4-ethylenedioxythiophene), polyaniline and ortho-phenylenediamine are frequently applied in sensor design. Some other materials that can be molecularly imprinted are also overviewed in this review. Among many imprintable materials conducting polymer, polypyrrole is one of the most suitable for molecular imprinting of various targets ranging from small organics up to rather large proteins. Some attention in this review is dedicated to overview methods applied to design MIP-based sensing structures. Some attention is dedicated to the physicochemical methods applied for the transduction of analytical signals. Expected new trends and horizons in the application of MIP-based structures are also discussed.

Emerging porous organic polymers for biomedical applications

This review summarizes and discusses the recent progress in porous organic polymers for diverse biomedical applications such as drug delivery, biomacromolecule immobilization, phototherapy, biosensing, bioimaging, and antibacterial applications.

Phosphate based new organic polymer networks for efficient dye sorption and catalyst loading for chemo-selective reactivity

Phosphate-based porous organic polymers adsorb small cationic dyes efficiently and host gold nanoparticles for catalytic reduction of electron rich nitroaromatics.

Advances in Molecularly Imprinted Polymers Based Affinity Sensors (Review)

Recent challenges in biomedical diagnostics show that the development of rapid affinity sensors is very important issue. Therefore, in this review we are aiming to outline the most important directions of affinity sensors where polymer-based semiconducting materials are applied. Progress in formation and development of such materials is overviewed and discussed. Some applicability aspects of conducting polymers in the design of affinity sensors are presented. The main attention is focused on bioanalytical application of conducting polymers such as polypyrrole, polyaniline, polythiophene and poly(3,4-ethylenedioxythiophene) ortho-phenylenediamine. In addition, some other polymers and inorganic materials that are suitable for molecular imprinting technology are also overviewed. Polymerization techniques, which are the most suitable for the development of composite structures suitable for affinity sensors are presented. Analytical signal transduction methods applied in affinity sensors based on polymer-based semiconducting materials are discussed. In this review the most attention is focused on the development and application of molecularly imprinted polymer-based structures, which can replace antibodies, receptors, and many others expensive affinity reagents. The applicability of electrochromic polymers in affinity sensor design is envisaged. Sufficient biocompatibility of some conducting polymers enables to apply them as "stealth coatings" in the future implantable affinity-sensors. Some new perspectives and trends in analytical application of polymer-based semiconducting materials are highlighted.

Conjugated microporous polymers as an ideal platform for tunable emission via π-conjugation

Emissive conjugated microporous polymers were tunable from green to red via the π-conjugation effects in the vertex.

Conducting Polymers in the Design of Biosensors and Biofuel Cells

Fast and sensitive determination of biologically active compounds is very important in biomedical diagnostics, the food and beverage industry, and environmental analysis. In this review, the most promising directions in analytical application of conducting polymers (CPs) are outlined. Up to now polyaniline, polypyrrole, polythiophene, and poly(3,4-ethylenedioxythiophene) are the most frequently used CPs in the design of sensors and biosensors; therefore, in this review, main attention is paid to these conducting polymers. The most popular polymerization methods applied for the formation of conducting polymer layers are discussed. The applicability of polypyrrole-based functional layers in the design of electrochemical biosensors and biofuel cells is highlighted. Some signal transduction mechanisms in CP-based sensors and biosensors are discussed. Biocompatibility-related aspects of some conducting polymers are overviewed and some insights into the application of CP-based coatings for the design of implantable sensors and biofuel cells are addressed. New trends and perspectives in the development of sensors based on CPs and their composites with other materials are discussed.

Synthesis and Properties of Perylene-Bridge-Anchor Chromophoric Compounds

The quest to control chromophore/semiconductor properties to enable new technologies in energy and information science requires detailed understanding of charge carrier dynamics at the atomistic level, which can often be attained through the use of model systems. Perylene-bridge-anchor compounds are successful models for studying fundamental charge transfer processes on TiO₂, which remains among the most commonly investigated and technologically important interfaces, mostly because of perylene's advantageous electronic and optical properties. Nonetheless, the ability to fully exploit synthetically the substitution pattern of perylene with linker (= bridge-anchor) units remains little explored. Here we developed 2,5-di-tert-butylperylene (DtBuPe)-bridge-anchor compounds with t-Bu group substituents to prevent π-stacking and one or two linker units in both the peri and ortho positions, by employing a combination of Friedel-Crafts alkylations, bromination, iridium-catalyzed borylation, and palladium-catalyzed cross-coupling reactions. Photophysical characterization and computational analysis by density functional theory (DFT) and time-dependent DFT (TD-DFT) were carried out on four DtBuPe acrylic acid derivatives with a single or a double linker in peri (12b), ortho (15b), peri,peri (18b), and ortho,ortho (21b). The energies of the unoccupied orbitals {LUMO, LUMO + 1, LUMO + 2} are strongly affected by the presence of a π-conjugated linker, resulting in a stabilization of these states and a red shift of their absorption and emission spectra, as well as the loss of vibronic structure in the spectrum of the peri,peri compound, consistent with the strong bonding character of this substitution pattern.

Naked-eye sensing of phytic acid at sub-nanomolar levels in 100% water medium by a charge transfer complex derived from off-the-shelf ingredients

Naked-eye sensing of phytic acid, one of the most abundant antinutrients, was achieved in 100% water medium using a charge transfer complex, composed of pyranine and methyl viologen. Since both the ingredients are commercially available, the design of such sensory systems needs zero synthetic effort, which essentially makes it economically viable. Only the physical mixture of both of these compounds showed a color-changing response from brown to yellow in the presence of phytic acid with a turn-on fluorescence response (LOD: 0.56 nM). The electrostatic interaction leads to charge pairing between phytic acid and methyl viologen, which releases free pyranine in solution. Considering its high sensitivity, low-cost test strips were developed for the on-site detection of phytic acid, even in remote locations. Additionally, estimation of phytic acid was achieved in grain samples with a sufficiently high accuracy, as evident from a sufficiently low relative standard deviation (<5%).

Porphyrins as Colorimetric and Photometric Biosensors in Modern Bioanalytical Systems

Advances in porphyrin chemistry have provided novel materials and exciting technologies for bioanalysis such as colorimetric sensor array (CSA), photo-electrochemical (PEC) biosensing, and nanocomposites as peroxidase mimetics for glucose detection. This review highlights selected recent advances in the construction of supramolecular assemblies based on the porphyrin macrocycle that provide recognition of various biologically important entities through the unique porphyrin properties associated with colorimetry, spectrophotometry, and photo-electrochemistry.

Functional Polymers Structures for (Bio)Sensing Application-A Review

In this review we present polymeric materials for (bio)sensor technology development. We focused on conductive polymers (conjugated microporous polymer, polymer gels), composites, molecularly imprinted polymers and their influence on the design and fabrication of bio(sensors), which in the future could act as lab-on-a-chip (LOC) devices. LOC instruments enable us to perform a wide range of analysis away from the stationary laboratory. Characterized polymeric species represent promising candidates in biosensor or sensor technology for LOC development, not only for manufacturing these devices, but also as a surface for biologically active materials' immobilization. The presence of biological compounds can improve the sensitivity and selectivity of analytical tools, which in the case of medical diagnostics is extremely important. The described materials are biocompatible, cost-effective, flexible and are an excellent platform for the anchoring of specific compounds.

Advances in Conjugated Microporous Polymers

Conjugated microporous polymers (CMPs) are a unique class of materials that combine extended π-conjugation with a permanently microporous skeleton. Since their discovery in 2007, CMPs have become established as an important subclass of porous materials. A wide range of synthetic building blocks and network-forming reactions offers an enormous variety of CMPs with different properties and structures. This has allowed CMPs to be developed for gas adsorption and separations, chemical adsorption and encapsulation, heterogeneous catalysis, photoredox catalysis, light emittance, sensing, energy storage, biological applications, and solar fuels production. Here we review the progress of CMP research since its beginnings and offer an outlook for where these materials might be headed in the future. We also compare the prospect for CMPs against the growing range of conjugated crystalline covalent organic frameworks (COFs).

The effects of the crosslinking position and degree of conjugation in perylene tetraanhydride bisimide microporous polymers on fluorescence sensing performance

In this study, two fluorescence conjugated microporous polymers based on perylene tetraanhydride bisimide (DP4A0 and DP4A2) were prepared via Sonogashira-Hagihara cross-coupling polymerization for the efficient detection of o-nitrophenol (o-NP). They were well characterized via FT-IR, solid state 13C NMR, elemental analysis, and other material characterization techniques. The experiments proved that both CMPs possess high thermal and chemical stability and a porous nature with Brunauer-Emmett-Teller (BET) specific surface areas of 41.3 and 402.1 m2 g-1. Importantly, owing to signal amplification by the conjugated skeleton, DP4A0 and DP4A2 exhibit extremely high sensitivity to o-NP with K sv values of 1.83 × 104 and 1.69 × 104 L mol-1 and limits of detection of 5.73 × 10-9 and 7.36 × 10-9 mol L-1, respectively. The sensing performance of DP4A0 and DP4A2 was dependent on the position of crosslinking points and crosslinking density. Finally, super amplified quenching was considered the electron transfer mechanism and hydrogen bond interactions were also present.

Conjugated porous polymers: incredibly versatile materials with far-reaching applications

This review discusses conjugated porous polymers and focuses on relating design principles and synthetic methods to key properties and applications such as (photo)catalysis, gas storage, chemical sensing, energy storage and environmental remediation.

Exploration of advanced porous organic polymers as a platform for biomimetic catalysis and molecular recognition

This Feature article summarizes our progress in the design of biomimetic POPs for catalysis and molecular recognition with enhanced performance.

Simultaneous sensing of ferritin and apoferritin proteins using an iron-responsive dye and evaluation of physiological parameters associated with serum iron estimation

An iron-responsive optical probe has been developed for simultaneous sensing of both ferritin and apoferritin proteins at pH 7.4 in water. The compound showed an exclusive response (turn-off signal) towards ferritin among a wide range of proteins even at nanomolar concentration. In contrast, apoferritin dissociates the preformed iron complex and revives the green colored fluorescence of the native probe (turn-on signal). Subsequently, various parameters associated with the serum iron level are evaluated, which are beneficial for clinical diagnosis of many iron-related diseases, including anemia. Estimation of iron was achieved in a wide range of edible plant materials as well as pharmaceutical formulations. Subsequently, different kinds of natural water samples were screened for quantification of soluble iron contents. In addition to traditional spectroscopic tools, dye-coated paper strips were developed as an alternative strategy for onsite 'instrument-free' detection of iron. Highly specific bioimaging of Fe³⁺ was achieved in cervical cancer cells (HeLa).

A triazine-based conjugated microporous polymer composite for magnetic solid phase extraction of 5-nitroimidazoles coupled with UPLC-MS/MS for quantification

A triazine-based conjugated microporous polymer composite for magnetic solid phase extraction of 5-nitroimidazoles coupled with UPLC-MS/MS for quantification.