Electroconductive Polymer Research Articles

Design and characterization of electroactive gelatin methacrylate hydrogel incorporated with gold nanoparticles empowered with parahydroxybenzaldehyde and curcumin for advanced tissue engineering applications

Electroconductive polymers are the materials of interest for the fabrication of electro-conductive tissues. Metal ions through the redox systems offer polymers with electrical conductivity. In this study, we processed a gelatin methacrylate (GelMA) network with gold nanoparticles (GNPs) through a redox system with parahydroxybenzaldehyde (PHB) or curcumin to enhance its electrical conductivity. Induction of the redox system with both PHB and curcumin into the GelMA, introduced some new functional groups into the polymeric network, as it has been confirmed by H-NMR and FTIR. These new bonds resulted in higher electro-conductivity when GNPs were added to the polymer. Higher electroactivity was achieved by PHB compared to the curcumin-induced redox system, and the addition of GNPs without redox system induction showed the lowest electroactivity. MTT was used to evaluate the biocompatibility of the resultant polymers, and the PHB-treated hydrogels showed higher proliferative effects on the cells. The findings of this study suggest that the introduction of a redox system by PHB in the GelMA network along with GNPs can contribute to the electrochemical properties of the material. This electroactivity can be advantageous for tissue engineering of electro-conductive tissues like cardiac and nervous tissues.Graphical

Numerical solutions for magneto-convective boundary layer slip flow from a nonlinear stretching sheet with wall transpiration and thermal radiation effects

A mathematical model is presented for magnetohydrodynamic viscous incompressible flow of an electrically conducting Newtonian polymeric fluid from a moving permeable horizontal stretching sheet with variable magnetic field, momentum and thermal slip boundary conditions. The emerging nonlinear ordinary differential boundary value problem is solved numerically by the Runge-Kutta-Fehlberg fourth-fifth order numerical method in Maple symbolic software. The effects of the governing parameters on the dimensionless stream function, dimensionless flow velocity and the dimensionless temperature have been investigated, displayed graphically and discussed. It is found that greater momentum slip and magnetic field parameters reduce the dimensionless velocity. It is further observed that higher values of Prandtl number, thermal slip, and conductionradiation parameter (weaker radiation contribution) reduce the dimensionless temperature whilst stronger magnetic field increases the temperature due to the supplementary work expended in dragging the polymer against the action of the magnetic field which is dissipated as heat. Comparisons of numerical results with previous published results show an excellent agreement. The study finds applications in electro-conductive polymer (ECP) processing systems.

A Wireless, CRISPR-Polymer Dot Electrochemical Sensor for the Diagnosis of Bacterial Pneumonia and Multi-Drug Resistance.

Rapid and accurate diagnosis is crucial for managing the global health threat posed by multidrug-resistant bacterial infections; however, current methods have limitations in either being time-consuming, labor-intensive, or requiring instruments with high costs. Addressing these challenges, we introduce a wireless electrochemical sensor integrating the CRISPR/Cas system with electroconductive polymer dot (PD) nanoparticles to rapidly detect bacterial pathogens from human sputum. To enhance the electroconductive properties, we synthesized copper-ion-immobilized PD (PD-Cu), followed by conjugation of the deactivated Cas9 protein (dCas9) onto PD-Cu-coated Si electrodes to generate the dCas9-PD-Cu sensor. The dCas9-PD-Cu sensor integrated with isothermal amplification can specifically detect target nucleic acids of multidrug-resistant bacteria, such as the antibiotic resistance genes kpc-2 and mecA. The dCas9-PD-Cu sensor exhibits high sensitivity, allowing for the detection of ∼54 femtograms of target nucleic acids, based on measuring the changes in resistivity of the Si electrodes through target capture by dCas9. Furthermore, a wireless sensing platform of the dCas9-PD-Cu sensor was established using a Bluetooth module and a microcontroller unit for detection using a smartphone. We demonstrate the feasibility of the platform in diagnosing multidrug-resistant bacterial pneumonia in patients' sputum samples, achieving 92% accuracy. The current study presents a versatile biosensor platform that can overcome the limitations of conventional diagnostics in the clinic.

Preparation of cross-linked PANI/PVA conductive hydrogels for electrochemical energy storage and sensing applications

The tunability of flexible electro-conductive polymer hydrogel by retaining the gel-ness and swelling nature with significant electrical conductivity remains a challenging problem. Conductive hydrogel (CH) should exhibit gel-like behavior with an appreciable conductivity. The combined property of gel and conductivity depends on the relative proportion of the constituent components. Herein, we present the detailed investigation on the effect of composition of polyvinyl alcohol (PVA) and polyaniline (PANI) on the structure and properties of PANI/PVA conducting hydrogels. We have prepared a series of hydrogel by varying the ratio of PANI and PVA. We have observed that the property of the PANI/PVA hydrogel significantly depends on the PANI content in the hydrogel. The detailed analysis based on XRD reveals that the peak intensity at 2θ = 19.3° has been decreased and the bandwidth has been increased with increasing PANI content, implying a decrease in the degree of crystallinity and enhancing amorphous nature. The interaction between PANI and PVA is also evident from the change in FTIR spectra of OH group. Detailed morphological analysis shows the formation of well-interpenetrated structure of PANI and PVA. Swelling study and current-voltage measurement in DI water and artificial tear fluid show composition dependent gel and conducting behavior, respectively. Tuning the composition of PVA and PANI results the blend to possess adequate “gel” with improved flexibility and “conducting” nature, required for a conducting hydrogel (CH). We have shown the application of hydrogel as an electrode material for supercapacitor with significant cyclic stability (∼95 % after 1000 cycles). We have also presented the viability of CH as an enzymatic glucose biosensor, with a significant LOD (∼0.001 μM).

Pseudo-doping effect on structural and electrical properties of polyaniline-camphorsulfonic acid

Electroconductive polymers (ECP) are critical for the design of soft electronic and bioelectronic devices. Polyaniline:camphorsulfonic acid (PANI:CSA) is an example of a biocompatible and affordable ECP, whose electroconductivity is highly dependent on chain organization/conformation. PANI:CSA aggregation ordering is overlooked in most works, but it can greatly impact the performance of PANI:CSA-based devices and limit their applicability. A simple and cheap method to avoid random coil aggregation of PANI:CSA is to select solvents with pseudo-doping properties. This work presents a novel alternative solvent system, based on trifluoroethanol (TFE) and hexafluoropropanol (HFP) mixtures, capable of being removed without hampering the structural and electrical properties of PANI:CSA. For the first time, we present a systematic study that compares the performance of solvent systems containing different amounts of TFE and HFP, which, unlike m-cresol, the golden-standard of pseudo-doping, are easy to remove without compromising the ECP’s electroconductivity and biocompatibility. We also evaluate the influence of the processing method, drop-casting vs spin-coating, on the structural and electrical properties of the obtained samples. Samples obtained by spin-coating show a more consistent improvement in electroconductivity (σ(TFE) = 61 S cm−1, σ(TFE:HFP (50:50 vol)) = 70 S cm−1) and more intense near-infrared (NIR) absorption bands. Atomic force microscopy (AFM), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) indicate that samples processed with HFP and m-cresol have higher benzenoid content, lower random coil aggregation and more efficient CSA doping. The solvent system comprised of equal parts of TFE and HFP was found to simultaneously enhance the electrical properties and structural ordering of PANI:CSA. We believe our results are critical for the fabrication of PANI-based next generation bioelectronic devices.

Towards net-zero: CO2 capture and biogas purification through electric potential swing desorption to achieve SDGs 7 and 13

Currently, the potential of biomethane derived from biogas is substantial, positioning it to fulfill a considerable share of the United Kingdom’s total energy needs. The primary challenge associated with raw biogas lies in purifying it to produce biomethane, a process that necessitates the removal of carbon dioxide and hydrogen sulfide. Among the various methods, adsorption of activated carbon (AC) stands out as a particularly effective and cost-efficient approach for converting biogas into biomethane, provided that the regeneration of AC proves economically viable. In this research, a segment of activated carbon was utilized to assess the adsorption properties when exposed to a gas mixture of CO2, H2S, and N2 within a regenerative activated carbon setup. This investigation encompassed the analysis of adsorption and desorption behaviors, process capacities, and the impact of regeneration. To enhance the adsorption of CO2, electro-conductive polymers (ECPs) were incorporated into the AC samples, leading to an extension in breakthrough time. Subsequent to adsorption, the electric potential swing desorption (EPSD) was employed for in situ regeneration of activated carbon samples, involving potentials of up to 30 V. The findings exhibited that the newly introduced EPSD technique considerably diminished desorption durations for both H2S and CO2. Moreover, it successfully rejuvenated the accessible adsorption sites, resulting in reduced desorption times compared to the initial breakthrough time during adsorption. Consequently, the EPSD system proves to be a promising candidate for in situ regeneration of activated carbon to eliminate CO2 and H2S from biogas. Notably, this approach offers inherent advantages over conventional methods including thermal swing adsorption (TSA) and pressure swing adsorption (PSA) in terms of regeneration. The demonstrated method underscores the potential for more efficient and economically viable cycles of adsorption and desorption, thereby enhancing the overall biogas-to-biomethane conversion process to achieve SDGs 7 and 13 for clean and green energy applications.

Computation of couple stress electroconductive polymer from an exponentially stretching sheet

Magnetic polymer processing involves multiple physical phenomena and requires simultaneous consideration of rheological, hydromagnetic and thermal characteristics. Inspired by new developments in functional magnetic coating dynamics, the present article investigates the viscous magnetohydrodynamic non-Newtonian boundary layer flow of an incompressible, electrically conducting, couple stress, electroconductive polymer from an exponentially stretching sheet. The nonlinear boundary value problem is solved numerically by adopting shooting technique and bvp4c algorithm available in MATLAB software. Validation with the Adams-Moulton 2-step predictor corrector algorithm is included. The effects of non-Newtonian couple stress parameter, magnetic interaction number, mixed convection parameter, slip parameter, Prandtl and Eckert number on the primary and secondary velocities and temperature fields are visualized graphically. Greater hydrodynamic slip effect initially boosts the primary velocity near the wall but thereafter induces a decrement in it. However, a consistent improvement in secondary velocity is computed for greater slip parameter. Increasing Hall parameter strongly accelerates the secondary flow but only weakly accelerates the primary flow. Increasing magnetic interaction number decelerates the primary and secondary flow. Elevating magnetic number promotes the thermal boundary layer thickness and also the temperature. Couple stress effects generally accelerate both the primary and secondary flow.

Designing Electrical Stimulation Platforms for Neural Cell Cultivation Using Poly(aniline): Camphorsulfonic Acid.

Electrical stimulation is a powerful strategy to improve the differentiation of neural stem cells into neurons. Such an approach can be implemented, in association with biomaterials and nanotechnology, for the development of new therapies for neurological diseases, including direct cell transplantation and the development of platforms for drug screening and disease progression evaluation. Poly(aniline):camphorsulfonic acid (PANI:CSA) is one of the most well-studied electroconductive polymers, capable of directing an externally applied electrical field to neural cells in culture. There are several examples in the literature on the development of PANI:CSA-based scaffolds and platforms for electrical stimulation, but no review has examined the fundamentals and physico-chemical determinants of PANI:CSA for the design of platforms for electrical stimulation. This review evaluates the current literature regarding the application of electrical stimulation to neural cells, specifically reviewing: (1) the fundamentals of bioelectricity and electrical stimulation; (2) the use of PANI:CSA-based systems for electrical stimulation of cell cultures; and (3) the development of scaffolds and setups to support the electrical stimulation of cells. Throughout this work, we critically evaluate the revised literature and provide a steppingstone for the clinical application of the electrical stimulation of cells using electroconductive PANI:CSA platforms/scaffolds.

SYNTHESIS AND PROPERTIES OF POLYIMINES BASED ON DIALDEHYDES OF THE FURAN SERIES AND VARIOUS DIAMINES

In this work, the reactions of 2,5-diformylfuran (DFF) with various aromatic and aliphatic diamines were studied, and the physicochemical properties of the resulting polyimines were studied. Research on the synthesis of electro-conductive polymers and the study of their physicochemical properties attracts great interest in modern polymer science. A class of electrically conductive polymers that has been particularly attractive for research in the last half century are aromatic polyimines, which are also known as polyimines or Schiff-based polymers. DFF-based polymers are little studied due to the high cost of the monomer, which limits its synthetic application. The availability of DFF is made both by the development of economical methods for its production, the oxidation of 5-hydroxymethylfurfural (5-HMF), and by the provision of sustainable access to 5-HMF from biomass. Polyimines containing furan fragments were synthesized by low-temperature polycondensation of DFF, available from plant materials, and various aromatic diamines in ethanol. The resulting polymers were high-melting thermoplastics from yellow to orange. The polymers showed typical absorption bands characteristic of the stretching vibrations of the C=N group (about 1620 cm-1) in the infrared spectra and had high glass transition temperatures of more than 200 °C. The ionic conductivity of polyimines has been characterized by electrochemical impedance spectroscopy. The conductivity value for polyimines, doped with I2, reaches 1.24·10-4 S cm-1 (at 298 K and 100% relative humidity), which is one of the highest values of proton conductivity for polyimines doped without using metals or their salts. The resulting polymers can be used to manufacture composites with various fillers. For citation: Kataria Y.V., Klushin V.A., Kashparova V.P., Sokolova V.A., Smirnova N.V. Synthesis and properties of polyimines based on dialdehydes of the furan series and various diamines. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2023. V. 66. N 6. P. 6-12. DOI: 10.6060/ivkkt.20236606.6763.

Homotopy analysis of mixed convection flow of a magnetized viscoelastic nanofluid from a stretching surface in non-Darcy porous media with revised Fourier and Fickian approaches

This article addresses theoretically the mixed convection hydromagnetic flow of electrically conducting viscoelastic nanofluid from a vertical permeable stretching sheet in a non-Darcy porous medium with Cattaneo–Christov double-diffusion model to evaluate the heat transfer phenomena in steady boundary layer flow on a stretchable surface. In this regard, thermal and solutal hyperbolic wave relaxation effects are included for non-Fourier and non-Fickian models. Heat absorption is also included in the analysis. The Buongiorno two-component nanoscale model is adopted for simulating Brownian motion and thermophoretic body force effects. A non-Darcy drag force model is employed for the porous medium and the Reiner–Rivlin second-grade model for non-Newtonian characteristics. Via appropriate dimensionless similarity variables, the nonlinear dimensional partial differential conservation equations for momentum, energy and concentration with associated boundary conditions are rendered into a nonlinear dimensionless ordinary differential boundary value problem. The homotopy analysis method (HAM) is utilized to solve the boundary value problem and the impact of emerging parameters including thermal relaxation parameters, non-Newtonian material parameter, Darcy permeability parameter, porous inertial parameter and Hartmann magnetic number on the momentum, heat and mass transfer characteristics are visualized graphically and in tables. A 30th-order approximation for HAM is shown to produce sufficient accuracy for the velocity and temperature fields and a 40th-order estimates is adequate for the concentration field. It is observed that increasing the magnitude of thermal and solutal relaxation parameters has the opposite effect on the thermal and concentration distributions. The novelty of the work is the simultaneous inclusion of multiple effects (non-Fourier and non-Fickian thermal relaxation hyperbolic wave models, non-Darcy drag effects and heat generation/absorption) which are relevant to rheological nanomaterials processing and also the deployment of homotopy analysis as an alternative to conventional numerical methods such as finite differences, finite elements and MATLAB solvers. The study is relevant to the manufacture of electro-conductive polymers (ECPs) and smart (functional) magnetic nano-liquids.

Insights Into the Application of Polyaniline-Based Composites in Environmental Engineering

Environmental management demands innovative techniques for its protection and treatment. The essential agreement of the modern world is to overcome every issue in a sustainable way. The two major financial problems in this area are water pollution and material corrosion. Persistent, organic compounds such as pesticides have devastating effects on the water ecosystem. This problem can be solved by applying advanced treatment processes (ATPs) like membrane separation and photocatalysis. Additionally, the corrosion of metal materials needs to be prevented to preserve natural resources and reduce environmental concerns. Therefore, researchers are trying to develop tunable, multifunctional materials with broad applications. Employed materials in these operations must fulfill high criteria, like durability, stability, and chemical and optical activity, to make specified processes efficient and viable. Electroconductive polymers (ECPs) can meet the aforementioned standards. The most used ECP is polyaniline (PANI), due to its catalytic and electrochemical performances. These two properties are beneficial for both water purification and anticorrosion applications. The objectives of the paper are to represent various PANI-based composites utilized in the removal of different classes of pesticides during wastewater treatment by adsorption or photocatalytic degradation. Further corrosion inhibition, utilizing PANI-based inhibitors, will be discussed as well.

Comparative Analysis of a New Class of Symmetric and Asymmetric Supercapacitors Constructed on the Basis of ITO Collectors

The paper presents the results of research on new electroconductive polymer materials, based on polypyrrole, for the different supercapacitor constructions, i.e., the symmetric and asymmetric constructions. All the supercapacitors considered contain ITO collectors. Measurements of the complex impedance frequency characteristics were performed for these elements using the electrochemical impedance spectroscopy (EIS) method. Selected fractional-order models, known from the literature, have been used to model the impedance of these elements. The Particle Swarm Optimization (PSO) algorithm was used to estimate the model parameters. Selected estimation results, their comparison, and conclusions are also presented in the paper. The type of active electrolyte component has the greatest impact on the shape of the impedance frequency characteristics. In most cases, the highest capacitance values and the smallest resistance values were obtained for asymmetric supercapacitors.

Electrical Stimulation Increases Axonal Growth from Dorsal Root Ganglia Co-Cultured with Schwann Cells in Highly Aligned PLA-PPy-Au Microfiber Substrates.

Nerve regeneration is a slow process that needs to be guided for distances greater than 5 mm. For this reason, different strategies are being studied to guide axonal growth and accelerate the axonal growth rate. In this study, we employ an electroconductive fibrillar substrate that is able to topographically guide axonal growth while accelerating the axonal growth rate when subjected to an exogenous electric field. Dorsal root ganglia were seeded in co-culture with Schwann cells on a substrate of polylactic acid microfibers coated with the electroconductive polymer polypyrrole, adding gold microfibers to increase its electrical conductivity. The substrate is capable of guiding axonal growth in a highly aligned manner and, when subjected to an electrical stimulation, an improvement in axonal growth is observed. As a result, an increase in the maximum length of the axons of 19.2% and an increase in the area occupied by the axons of 40% were obtained. In addition, an upregulation of the genes related to axon guidance, axogenesis, Schwann cells, proliferation and neurotrophins was observed for the electrically stimulated group. Therefore, our device is a good candidate for nerve regeneration therapies.

Biocompatible Electroconductive Matrices for Tissue Engineering: A Comparative Study

Electroconductive polymer matrices intended for use in tissue engineering were prepared of various biocompatible polymers (polyimide, chitosan, copolyamide) modified with different conductive additives (graphene, carbon nanotubes, polypyrrole). Biocompatibility of matrices derived from composite materials was confirmed using human dermal fibroblast culture. Conducting properties of the matrices in the dry state and in physiological solution were investigated upon applying cyclic external potential. The influence of electron-conducting and ion-conducting components of the obtained composites on the current passing through the matrix and the shape of the current sweep is discussed.

Axisymmetric radiative titanium dioxide magnetic nanofluid flow on a stretching cylinder with homogeneous/heterogeneous reactions in Darcy-Forchheimer porous media: Intelligent nanocoating simulation

Modern nanomaterials coating processes feature high temperature environments and complex chemical reactions required for the precise synthesis of bespoke designs. Such flow processes are extremely complex and feature both heat and mass transfer in addition to viscous behaviour. Intelligent nano-coatings exploit magnetic nanoparticles and can be manipulated by external magnetic fields. Mathematical models provide an inexpensive insight into the inherent characteristics of such coating dynamics processes. Motivated by this, in the current work, a novel mathematical model is developed for dual catalytic reactive species diffusion in axisymmetric coating enrobing forced convection boundary layer flow from a linearly axially stretching horizontal cylinder immersed in a homogenous non-Darcy porous medium saturated withmagnetic nanofluid. Homogeneous and heterogeneous reactions, heat source (e.g. laser source) and non-linear radiative transfer are included. The Tiwari-Das nanoscale model is deployed. A Darcy-Forchheimerdrag force formulation is utilized to simulate both bulk porous drag and second order inertial drag of the porous medium fibres. The magnetic nanofluid is an aqueous electroconductive polymer comprising base fluid water and magnetic TiO2 nanoparticles. The TiO2 nanoparticles are one chemically reacting species (A) and a second species (B) is also present (e.g. oxygen) which also reacts chemically. Viscous heating and Ohmic dissipation are also included to produce a more physically realistic thermal analysis. The non-linear conservation equations proposed here with species diffusion (species A and B) are transformed via an appropriate stream function and scaling variables into a set of non-linear united multi-degree ODEs. The rising nonlinear ordinary differential boundary value problem is solved with four-point Gauss-Lobotto formulae in the MATLAB bvp5c routine. Validation is conducted with an Adams-Moulton predictor–corrector numerical scheme (AM2 coded in Unix). The widespread visualization of velocity, temperature, species A concentration, species B concentration, skin friction, local Nusselt number and species A and B local Sherwood numbers is included. For the higher Schmidt number the momentum diffusion rate exceeds the species diffusion rate and this will produce a depression in concentration values. Further, increasing Darcian parameter retards the local Nusselt number magnitudes since higher permeability corresponds to sparsity in the solid fibres, reduction in thermal conduction and a concomitant cooling of the cylinder surface.

Evolution of the Surface Structure and Functional Properties of the Electroconducting Polymer Coatings onto Porous Films

Composite systems containing electroconducting polymer coatings (polyaniline and polypyrrole) applied to porous films of semicrystalline polymers (polyethylene, polypropylene, and polyvinylidene fluoride) have been prepared. Porous supports were obtained in the process based on polymer melt extrusion with subsequent annealing, uniaxial extensions, and thermal stabilization. Conducting coatings were formed by the oxidative polymerization of the monomers directly onto the porous supports. The structure (overall porosity, permeability, pore sizes, factor of orientation) and morphology (specific surface and character of the film surface) of the supports were characterized by sorptometry, filtration porosimetry, atomic force microscopy (AFM), and X-ray scattering techniques. It was observed that the porous supports have a strongly developed relief surface which is formed in the pore formation process. It was proven by scanning electron microscopy (SEM) that the porous supports have an oriented structure, and the surface of the composites is defined by the morphology inherent in the conducting component. It was shown that these composites (porous support/conducting coating) demonstrate electric conductivity both along the surface and between surfaces. It was demonstrated that the deposition of conducting coatings leads to an increase in the water wettability of the composites compared with pronounced hydrophobic supports. The composites are characterized by good adhesion between components due to a relief film surface as well as high mechanical strength and elasticity provided by the oriented character of the supports.

Magneto Casson-Carreau Fluid Flow through a Circular Porous Cylinder with Partial Slip

In the current study, a comparative analysis of two-dimensional heat transfer by the free convective flow of non-Newtonian Casson and Carreau fluid in electro-conductive polymer on the outside surface of a horizontal circular cylinder under slip and radial magnetic field effects is regarded. The Casson and Carreau fluid model formulation were first developed for the problem of the boundary layer of the horizontal circular cylinder and by using non-similarity transformations, the combined governing partial differential equations are translated into ordinary differential equations. The differential equations obtained are resolved by the Keller Box Method (KBM). The impact of the key parameters, the rate of heat transfer and skin friction is evaluated through graphs and tables. The result reveals that an increase in magnetic number decreases the velocity field of both Casson and Carreau fluid also Casson fluid is higher values when compared to Carreau fluid in variation of magnetic number.

Multi-stimuli Responsive Natural Fibers Immobilized with Silver Nanoparticles via Plasma-activated Generation of Polyaniline

Functionalization of natural fibers with electroactive polymeric materials can create conductive surfaces with multifunctional properties. Herein, we develop smart fibers using plasma supported coating of wool fabrics with various polyaniline derivatives (PANi) in the presence/absence of in-situ prepared silver nanoparticles (AgNPs). Nanostructural thin film of PANi was synthesized in-situ employing plasma-pretreatment to assess the polymerization process. AgNPs were immobilized in-situ during the formation of PANi starting from silver nitrate (AgNO3) by taking benefit of the reducing ability from the electroconductive polymer derivatives. Some selected electroactive polymers were applied starting from aromatic amines, including m-anisidine, o-phenylenediamine and p-nitroaniline. The morphological characteristics of the produced fabrics were studied by scan electron microscope (SEM). The chemical analysis was studied by energy-dispersive X-ray analyzer and Fourier transform infrared (FTIR) spectra. As monitored by CIE Lab colorimetric measurements, instant reversible color variations were monitored by recording the colorimetric measurements of the produced sensor fabrics. By changing the sort of the electroactive polymer and the inclusion of silver nanoparticles, the imparted characteristics of the developed wool fabrics, including antimicrobial, electroactivity and stimuli-responsive effects were explored for a diversity of promising medical applications.

Reusable biosensor-based polymer dot-coated electrode surface for wireless detection of bacterial contamination

Biosensor development for bacterial detection is critical to preventing infectious disease outbreaks caused by bacterial contamination. Recent studies have focused on colorimetric sensors, but high limit of detection (LOD) has restricted their application for sensitive bacterial detection. Here, we designed a reusable, sensitive smartphone-based electrochemical biosensor which uses electroconductive boronic acid-modified polymer dot (B-PD)-coated electrode to detect bacterial contamination. The pH-selective boronic acid in B-PD promotes binding between sensor and bacteria via increased diol-diol kinetics of boronic acid at pH 7.4. B-PD-coated electrodes can detect both gram-negative (E. coli) and gram-positive (S. aureus) bacteria by observing the conductivity change after attachment (101-107 CFU/mL), with high sensitivity, as indicated by low LOD (E. coli=100.8 CFU/mL, S. aureus=101 CFU/mL). The electronic signal from bacterial detection is transmitted to smartphone by connecting B-PD-coated electrode with wireless microcontroller, which allows for simple in-line monitoring. This biosensor demonstrated excellent performance in detecting bacteria in real environmental samples, along with good selectivity towards bacteria, even in the presence of interfering compounds. Moreover, by maintaining boronic acid-diol interaction, B-PD-coated electrode can be reused after applying pH shock (pH < 6) up to four cycles. Thus, this system offers simple approach for bacteria monitoring with high sensitivity and reusability.

Natural and synthetic polymeric scaffolds used in peripheral nerve tissue engineering: Advantages and disadvantages

The nervous system is a compound network of nerves, cells and is a vital part of the body. The injuries to this system can occur either via traumatic hurt happening after the accident, disease, tumorous outgrowth, or surgical side results. The regeneration of the nervous system is complex and takes big challenges to researchers. Nerve tissue engineering (NTE) is the most promising approach to repair nerve tissue in human health care. One of the most common solutions widely used for repairing functions in damaged neural tissues utilizes polymeric materials either natural or synthetic in origin. Polymers are able to develop into help structures, such as scaffold, electrospun matrices, and nerve conduit for promoting the regeneration of the damaged neural tissues that many investigations have shown. As usual, synthetic polymers suggest better structural stability and mechanical properties while natural polymers are highly useful for their high biocompatibility and natural biodegradation properties. However, low mechanical characteristics, processing difficulties and, thermal sensitivity that commonly need the use of solvents, limit the efficacy of natural polymers, stimulating researchers to blend them with synthetic or electroconductive polymers. Mostly, the blending of natural and synthetic allows for expanding polymeric conduits that help to mimic the substrate environment of healthy neural tissues. This review represents the most advanced and various recent findings in terms of the forms of natural and Synthetic polymers used in peripheral NTE, advantages, and disadvantages.