Electrodeposition Of Polymers Research Articles

PANDA: a self-driving lab for studying electrodeposited polymer films.

We introduce the polymer analysis and discovery array (PANDA), an automated system for high-throughput electrodeposition and functional characterization of polymer films. The PANDA is a custom, modular, and low-cost system based on a CNC gantry that we have modified to include a syringe pump, potentiostat, and camera with a telecentric lens. This system can perform fluid handling, electrochemistry, and transmission optical measurements on samples in custom 96-well plates that feature transparent and conducting bottoms. We begin by validating this platform through a series of control fluid handling and electrochemistry experiments to quantify the repeatability, lack of cross-contamination, and accuracy of the system. As a proof-of-concept experimental campaign to study the functional properties of a model polymer film, we optimize the electrochromic switching of electrodeposited poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) films. In particular, we explore the monomer concentration, deposition time, and deposition voltage using an array of experiments selected by Latin hypercube sampling. Subsequently, we run an active learning campaign based upon Bayesian optimization to find the processing conditions that lead to the highest electrochromic switching of PEDOT:PSS. This self-driving lab integrates optical and electrochemical characterization to constitute a novel, automated approach for studying functional polymer films.

Understanding Polymer Electrodeposition and Conducting Polymer Modified Electrodes Using Electrochemistry, Spectroscopy, and Scanning Probe Microscopy.

Conducting polymers are critically important materials in organic electronic platforms relevant to sustainability (organic photovoltaics and organic light-emitting diodes) and wearable electronics (organic electrochemical transistors). However, most chemistry students do not receive formal training in the fundamental properties and extensive characterization of these fascinating materials. Described here are four scaffolded learning modules adapted from the primary literature and designed to build the fundamental understanding and practical skills necessary for productive contribution to emerging research in the field of conducting polymers and conducting polymer modified electrodes (CPMEs). These activities were performed by first-year chemistry graduate students and have been used in the lab to orient and equip new student researchers with the electrochemical, spectroscopic, and spectroelectrochemical skillsets central to working in CPMEs. First year master's students and undergraduate student researchers worked individually to complete data collection, analysis, and interpretation over three 4 h periods with additional time for sample preparation and imaging. Alternatively, one or more of these modules can be adapted and performed by pairs or groups of three over two 4 h lab periods as part of an undergraduate course such as instrumental analysis, polymers, and macromolecules, or as a capstone experience; instructions for these and other modifications are as described herein. If lab equipment and/or available time are limiting factors, sufficient sample data are provided for use as dry laboratories. Through completion of these modules, student researchers learn how to build chemically rational explanations for the electrochemical and spectroscopic signals, to collectively examine data from multiple complementary characterization techniques, and to extract enabling structure-property relationships, all while coming to see themselves as researchers and members of a worldwide scientific community.

One-pot electrodeposition of multilayered 3D PtNi/polymer nanocomposite. H2O2 determination in aerosol phase

In this work, 3D-structured nanocomposites were synthesized in one pot by electrochemical deposition of alternating layers of an azo type polymer (polyazure-A) with platinum and nickel nanoparticles. The hybrid PtNi/poly(AzA) film was electrochemically deposited on screen-printed carbon electrodes by layer-by-layer assembly as a function of the number of cyclic voltammograms for electrodeposition of the conducting polymer and the electrode potential applied for electro-reduction of the metal salts. The physicochemical characteristics of the resulting films were studied using electrochemical and microscopic techniques. The 3D molecular nanoarchitecture presents a hollow porous structure dependent on the electrode potential set for the electro-reduction of Pt and Ni nanoparticles. The electrochemical sensor was validated in terms of sensitivity, limit of detection, stability and repeatability, exhibiting a highly sensitive H2O2 detection, with LoD 68.5 nM (S/N = 3) at 0.05 V vs. Ag-SPCE for the electrode modified with 20 cycles for the conducting polymer electrodeposition and −2.0 V for metal ions reduction. The aim of this work also included the outcome of the electrochemical sensor after incorporating the room temperature ionic liquid 1‑butyl‑2,3-dimethylimidazolium tetrafluoroborate within the PtNi/poly(AzA) film, which notably improved the analytical parameters of the system, with LoD 14.5 nM at the same potential. Therefore, as proof of concept, the PtNi/poly(AzA) film-based electrode was explored towards the suitability of an electrochemical sensor for the determination of hydrogen peroxide in aerosol phase. The outstanding features of the PtNi/poly(AzA) film-based electrode modified with the aforementioned ionic liquid allowed for the continuous monitoring of H2O2 in an aerosol stream generated with an ultrasonic diffuser at the low applied potential of 0.05 V. In addition, monitoring H2O2 samples through a series of ON/OFF switches for over 3 h, the sensor provided a fast and reproducible response.

A Portable Molecularly Imprinted Sensor for On-Site and Wireless Environmental Bisphenol A Monitoring.

The detection of pollutant traces in the public and environmental waters is essential for safety of the population. Bisphenol A (BPA) is a toxic chemical widely used for the production of food storage containers by plastic industries to increase the storage ability. However, the insertion of BPA in water medium leads to serious health risks. Therefore, the development of low-cost, practical, sensitive, and selective devices to monitor BPA levels on-site in the environment is highly needed. Herein, for the first time, we present a homemade portable potentiostat device integrated to a laser-scribed graphene (LSG) sensor for BPA detection as a practical environmental pollutant monitoring tool. Recently, there has been an increasing need regarding the development of graphene-based electrochemical transducers (e.g., electrodes) to obtain efficient biosensing platforms. LSG platform is combined with molecularly imprinted polymer (MIP) matrix. LSG electrodes were modified with gold nanostructures and PEDOT polymer electrodeposition to create a specific MIP biomimetic receptor for ultrasensitive BPA detection. The sensing device has a Bluetooth connection, wirelessly connected to a smartphone providing high sensitivity and sensitivity (LOD: 3.97 nM in a linear range of .01–10 µM) toward BPA. Two commercial bottled water samples, tap water, commercial milk, and baby formula samples have been used to validate the reliability of the portable sensor device.

A “Clickable” Electrodeposited Polymer Films Based on 3‐Ethynylthiophene for the Covalent Immobilization of Proteins. Application to a Label‐free Electrochemical Immunosensor for Escherichia Coli and Staphylococcus Aureus Determination

AbstractAn original electrodeposited polymer film, based on 3‐ethynylthiophene, for covalent immobilization of proteins via “click” reaction of copper catalyzed azide‐alkyne cycloaddition was developed. The best characteristics have demonstrated the layer‐by‐layer immobilized 3,4‐ethylendioxythiophene‐3‐ethynylthiophene composite film. The bovine serum albumin and antibodies have been successfully immobilized on the surface of planar platinum electrode. The approach has been applied to label‐free electrochemical immunosensors for Escherichia coli and Staphylococcus aureus determination. The immunosensors demonstrated LODs 7.2 CFU/mL for Escherichia coli and 15.9 CFU/mL for Staphylococcus aureus, linear range 102–106 CFU/mL and could be promising for environmental and food control.

Methodology for Determination of the Key Parameters of Conjugated Polymer Electrodeposition, Based on a Combination of Spectroelectrochemistry and Electrochemical Quartz Crystal Microbalance

Methodology based on a combination of experimental data obtained by in situ methods of spectroelectrochemistry and electrochemical quartz crystal microbalance has been proposed for determination of the key parameters of the conjugated polymer deposition on the electrode surface via monomer electrooxidation. These parameters are: the current efficiency of the process, the charge spent per an oxidized monomer molecule, the number of monomer units inside the deposited film, and the average number of valence bonds per one monomer unit inside the film. Besides, the electrochemical quartz crystal microbalance method applied to the discharge process of the electropolymerized film allows determining the average charging (oxidation) degree of the monomer unit at the polymerization potential and the degree of the solvent participation in the polymer’s redox transitions. The applicability of the proposed approach has been demonstrated by example of magnesium polyporphine films obtained by oxidation of unsubstituted magnesium porphine on inert electrode in acetonitrile solution at a low potential.

Fabrication and electrochemical properties of flow-through polypyrrole and polypyrrole/polypyrrole nanoarrays

Flow-through polypyrrole (PPY) nanoarrays are well tailored into nanopore, nanotube-in-nanopore and nanorod-in-nanopore structures to act as free-standing supercapacitor electrodes through anodization, electro-polymerization deposition and chemical corrosion processes. Independent TiO2 nanotube array is prepared to act as well-aligned and ordered temperate by an anodic oxidation of titanium sheet. Polypyrrole (PPY) was selectively coated on the external surface and/or internal surface of TiO2 nanotubes to form PPY/TiO2 and PPY/TiO2/PPY through a controlled pulse voltammetry electrodeposition process. Polypyrrole (PPY)/ Polypyrrole (PPY) nanotube-in-nanopore and nanorod-in-nanopore arrays can be formed by HF corrosion dissolution of TiO2 template from PPY/TiO2/PPY. Alternatively, PPY nanopore array can be formed by removing TiO2 template from PPY/TiO2. Polypyrrole (PPY) nanopore array has the pore diameter of 130–200 nm and wall thickness of 25–40 nm. Polypyrrole (PPY) Polypyrrole (PPY)/Polypyrrole (PPY) nanotube-in-nanopore array has the pore diameter of 135–225 nm, nanopore wall thickness of 25–45 nm and nanotube diameter of 90–135 nm. Polypyrrole (PPY)/ Polypyrrole (PPY) nanorod-in-nanopore array has the pore diameter of 115–215 nm, nanopore wall thickness of 20–35 nm and nanorod diameter of 85–135 nm. All these PPY and PPY/PPY nanoarrays have the total length of 0.9–1.1 μm and keep flow through and ordered alignment structure contributing to feasible electrolyte ion diffusion. Electroactive PY nanopore, PPY/PPY nanotube-in-nanopore and PPY/PPY nanorod-in-nanopore arrays directly become free-standing electrodes to achieve the specific capacitance of 13.2, 16.7 and 18.3mF cm−2 at 0.25 mA cm−2 in 1.0 M H2SO4 electrolyte and the rate capacity retention of 77.3, 77.2 and 77.0% at 1.5 mA cm−2. Well-tailored and flow-through PPY and PPY/PPY nanoarrays can act as the promising polymer electrode materials for electrochemical energy storage.

The Study of Synthesis Mechanism of Poly-Neutral Red and Its Electrocatalytic Property

１． Intention Concentration of carbon dioxide (CO2) in the atmosphere has steadily increased since industrial revolution. Despite the recent significant cost reduction of renewable electricity by solar and wind, their intermittency hinders the total shift to renewable energy. It is urgently needed to develop technologies for fast conversion of electrical energy into storable chemical energy by electrolysis, e.g., by water splitting and CO2 reduction. Stable and high-performance electrocatalysts are essential but must be developed without depending on precious metals for the real use and sustainability of the technology. Recently, we have demonstrated high and stable electrocatalytic properties of conductive organic polymers, such as polydopamine (PDA) and polyguanine (PGA) for hydrogen evolution reaction (HER) and CO2 reduction reaction (CO2RR)1,2). Hydrogen bonding N and O atoms introduced to these polymers are expected to stabilize the reaction intermediates for their high catalytic activities. In this study, a phenazine dye, neutral red (NR) was employed as the monomer to obtain a metal-free catalyst. NR bears many amino functions to make it electropolymerizable just like poly-aniline (electropolymerization deposition, to be called EPD). Also, oxidative chemical vapor deposition (oCVD) was employed to obtain PNR. Synthesis, characterization and comparison of the catalytic activities of PNR by EPD and oCVD are discussed. ２． Experiment EPD of PNR onto carbon felt (CF) was carried out by cycling potential between -1 and +1 V vs. Ag/AgCl for 100 cycles in an aqueous solution containing 0.2 mmol/L NR and 0.5 mol/L KNO3 (pH 5) at 50 mV/s. oCVD of PNR was performed in a three-zone quartz tube furnace under N2 flow, while setting the temperature for NR, sulfuric acid and CF at 375, 220 and 100ºC, respectively, for 240 min. PNR-modified as well as bare CF electrodes were measured under N2 and CO2 in a 1 M KNO3 (pH 7) for their catalytic activities for HER and CO2RR. ３． Result While bare carbon felt (CF) electrode does not show any catalytic activity towards CO2RR, showing about -3 mA cm-2 current at –1 V vs. Ag/AgCl, supposedly dominated by that for HER, the PNR coated CFs show enhanced current (Fig. 1a). That by EPD gives about -5 and -6 mA under N2 and CO2, respectively, indicating its moderate catalytic activity for HER and CO2RR. PNR prepared by oCVD, on the other hand, gives -6 and -12 mA, to demonstrate its superior activity, especially for CO2RR. Chronoamperogram measured during long term electrolysis for 17 h at the oCVD PNR electrode indicates reasonable stability of the catalysis (Fig 1b). These results already nicely confirm catalytic activity of PNR for its conductivity and hydrogen-bonding ability. H. Coskun et al., Sci. Adv. 3, e1700686 (2017).H. Coskun et al., Adv. Mater. Interf. 10, 1901364 (2019). Figure 1

Synthesis of Poly-Neutral Red and Its Electrocatalytic Property Towards CO2 Reduction Reaction

Concentration of carbon dioxide (CO2) in the atmosphere has steadily increased since industrial revolution. Despite the recent significant cost reduction of renewable electricity by solar and wind, their intermittency hinders the total shift to renewable energy. It is urgently needed to develop technologies for fast conversion of electrical energy into storable chemical energy by electrolysis, e.g., by water splitting and CO2 reduction. Stable and high-performance electrocatalysts are essential but must be developed without depending on precious metals for the real use and sustainability of the technology.Recently, we have demonstrated high and stable electrocatalytic properties of conductive organic polymers, such as polydopamine (PDA) and polyguanine (PGA) for hydrogen evolution reaction (HER) and CO2 reduction reaction (CO2RR)1,2). Hydrogen bonding N and O atoms introduced to these polymers are expected to stabilize the reaction intermediates for their high catalytic activities. In this study, a phenazine dye, neutral red (NR) was employed as the monomer to obtain a metal-free catalyst. NR bears many amino functions to make it electropolymerizable just like poly-aniline (electropolymerization deposition, to be called EPD). Also, oxidative chemical vapor deposition (oCVD) was employed to obtain PNR. Synthesis, characterization and comparison of the catalytic activities of PNR by EPD and oCVD are discussed.EPD of PNR onto carbon felt (CF) was carried out by cycling potential between -1 and +1 V vs. Ag/AgCl for 100 cycles in an aqueous solution containing 0.2 mmol/L NR and 0.5 mol/L KNO3 (pH 5) at 50 mV/s. oCVD of PNR was performed in a three-zone quartz tube furnace under N2 flow, while setting the temperature for NR, sulfuric acid and CF at 375, 220 and 100ºC, respectively, for 240 min. PNR-modified as well as bare CF electrodes were measured under N2 and CO2 in a 1 M KNO3 (pH 7) for their catalytic activities for HER and CO2RR.While bare carbon felt (CF) electrode does not show any catalytic activity towards CO2RR, showing about -3 mA cm-2 current at –1 V vs. Ag/AgCl, supposedly dominated by that for HER, the PNR coated CFs show enhanced current (Fig. 1a). That by EPD gives about -5 and -6 mA under N2 and CO2, respectively, indicating its moderate catalytic activity for HER and CO2RR. PNR prepared by oCVD, on the other hand, gives -6 and -12 mA, to demonstrate its superior activity, especially for CO2RR. Chronoamperogram measured during long term electrolysis for 17 h at the oCVD PNR electrode indicates reasonable stability of the catalysis (Fig 1b). These results already nicely confirm catalytic activity of PNR for its conductivity and hydrogen-bonding ability.

Non-enzymatic Electroanalytical Sensing of Glucose Based on Nano Nickel-Coordination Polymers-Modified Glassy Carbon Electrode

Herein, we introduce a simple set of experiments to construct non-enzymatic glucose sensors. The modification procedure was initiated by electrodeposition of nickel-coordination polymers (denoted henceforth as Ni-CPs) at the surface of glassy carbon (GC) electrode decorated with carbonnanotubes (CNTs). The electrochemical sensing of glucose occurred through the electrocatalytic oxidation of glucose by the Ni-CP using the CNTs as a high-area catalyst support. During potential cycling, the continuous chemical regeneration of the Ni(II) in the reaction between Ni(III) and glucose expresses itself as a dramatic enhancement of the anodic current pertaining to the Ni(III)/Ni(II) redox couple. Effects of various factors such as scan rate and solution pH were evaluated. For the optimized sensor the detection limit was as low as 2.1 μM glucose and with a linear response extending up to 400 μM. The modified electrode showed good reproducibility, excellent anti-interference performance, and high stability during the electrochemical experiments. Moreover, the analytical function of the non-enzymatic sensors for quantitative detection of glucose was assessed in real samples with satisfying results.

Electrodeposition Assisted Dynamic Assemblies of Chitosan/Alginate Composite Multi-Membrane

Electrodeposition of natural polymer as an effective approach to improve bioactivity of the conductive substrate has receives much attentions in medical and other applications. In this work, we developed a novel chitosan/alginate (CS/ALG) multi-membrane on titanium plate via the electrodeposition assisted dynamic assembly approach. Specifically, the electrical signal induced CS coating can serve as a versatile platform for layer by layer assemblies of ALG into the multi-membrane through strong electrostatic interaction. The prepared multi-membranes exhibit great swelling performance and excellent mechanical properties at dried states, with the tensile stress and strain values reaching to 58.2 MPa and 4.25 % for the 10 layers sample. In summary, we believe such green, low cost and rapid fabrication approach and mild processing environment would spur great potential for construction of multi-functional coating and smart drug elution system on the conductive implants.

Electrodeposited PEDOT:Nafion Composite for Neural Recording and Stimulation.

Microelectrode arrays are used for recording and stimulation in neurosciences both in vitro and in vivo. The electrodeposition of conductive polymers, such as poly(3,4-ethylene dioxythiophene) (PEDOT), is widely adopted to improve both the in vivo recording and the charge injection limit of metallic microelectrodes. The workhorse of conductive polymers in the neurosciences is PEDOT:PSS, where PSS represents polystyrene-sulfonate. In this paper, the counterion is the fluorinated polymer Nafion, so the composite PEDOT:Nafion is deposited onto a flexible neural microelectrode array. PEDOT:Nafion coated electrodes exhibit comparable in vivo recording capability to the reference PEDOT:PSS, providing a large signal-to-noise ratio in a murine animal model. Importantly, PEDOT:Nafion exhibits a minimized polarization during electrical stimulation, thereby resulting in an improved charge injection limit equal to 4.4 mC cm-2 , almost 80% larger than the 2.5 mC cm-2 that is observed for PEDOT:PSS.

Indirect bipolar electrodeposition of polymers for the controlled design of zinc microswimmers

Abstract Self-propelled micro/nanoswimmers performing directional motion are of great potential nowadays in the frame of nanotechnology. The general methods for breaking the symmetry in such systems, which is the essential condition for inducing motion, are template-based, leading to asymmetric objects. In the present work, a new concept using the principles of indirect bipolar electrochemistry is proposed for the design of asymmetric metal/polymer objects. Zinc has been selected as a metal as it allows the subsequent generation of hydrogen gas bubbles when exposed to acidic aqueous solutions. The asymmetric deposition of a polymer shell on the metal leads to propulsion of the particles in a controlled direction.

The design of superhydrophobic stainless steel surfaces by controlling nanostructures: A key parameter to reduce the implantation of pathogenic bacteria

Reducing bacterial adhesion on substrates is fundamental for various industries. In this work, new superhydrophobic surfaces are created by electrodeposition of hydrophobic polymers (PEDOT-F4 or PEDOT-H8) on stainless steel with controlled topographical features, especially at a nano-scale. Results show that anti-bioadhesive and anti-biofilm properties require the control of the surface topographical features, and should be associated with a low adhesion of water onto the surface (Cassie-Baxter state) with limited crevice features at the scale of bacterial cells (nano-scale structures).

Single-Step Coelectrodeposition of Hybrid Silica Nanocomposite Directs the Fabrication of Free-Standing and Transferal Conducting Polymer Thin Films

Conducting polymers have fascinated scientists over the years due to their superior properties and potential technological applications in optoelectronic devices, sensors, coatings, flexible electronics, electrocatalysis, tissue engineering, batteries, etc.1-3 However, the poor mechanical properties, stability and processability of the conductive polymer materials have limited such applications. Doping the conductive polymer material with inorganic components through the formation of organic–inorganic hybrid composites is an appealing route to overcome these problems. Silica is a potential candidate as the inorganic component in such hybrid composites due to its improved mechanical strength, chemical and thermal stability, tunable structure and porosity. Conducting polymers can be prepared by oxidizing the monomer solution using oxidizing agents, such as FeCl3 or by applying an anodic potential. On the other hand, silica can be prepared electrochemically via cathodic deposition of the silane monomers.4 To date, there is no available strategy to simultaneously synthesize silica-conducting polymer hybrid composites using a single deposition potential.3 Silica-conducting polymer hybrid composites are generally prepared in a two-step process that involves anodic deposition of the conducting polymer followed by cathodic deposition of the silica and vice versa.3Herein, we report on several new findings based on the combination of electrodeposition, sol-gel chemistry and electropolymerization processes. First, silica can be electrodeposited from strongly acidic solution of pH ~ 1 containing the silane monomers. Second, silica-conducting polymer and silica-metal-conducting polymer hybrid nanocomposites can be fabricated by cathodic deposition in a one-step process. The mechanism of the electropolymerization process under cathodic conditions is different from that occurring under anodic potentials, which allows the formation of new structures and morphologies and provides new avenues for material synthesis that cannot be achieved using conventional anodic methods. Third, the preparation of free standing and transferable thin films was achieved by two different routes: (a) silica etching due to the different kinetics for silica and the conducting polymer electrodeposition; (b) by dissolving the oxidizable electrode material in an acidic solution. The obtained silica-conducting polymer thin films can be immobilized on a variety of substrates, such as gold, ITO, glassy carbon, copper and even glass, which enables the preparation of cheap conducting polymer-based sensors and miniaturized devices. The as-prepared silica-conducting polymer and silica-metal-conducting polymer hybrid nanocomposites were characterized by XRD, surface profilometry, BET, EDX, SEM and cyclic voltammetry.

Parahydrophobic Surfaces by Electrodeposition of PEDOT Polymers with Aromatic Groups

We report the electropolymerization of five 3,4-ethylenedioxythiophene (EDOT) monomers containing different aromatic groups (phenyl, diphenyl, biphenyl, naphthalene, and pyrene). While with phenyl, diphenyl, biphenyl, and naphthalene the polymerization occurs on the EDOT moiety, with pyrene both the EDOT and the pyrene moieties polymerize. Their electrodeposition gives rise to different surface structures with parahydrophobic properties (water apparent contact angle θ > θY, where θY corresponds to the Young angle of the smooth surface of the same materials). The highest properties are obtained with PEDOT-BiPh (θ = 134.6° and extremely high water adhesion). The results are due to the combination of surface structures with intrinsically hydrophilic polymers (θY of the smooth polymer <90°).

Superhydrophobic surface properties with various nanofibrous structures by electrodeposition of PEDOT polymers with short fluorinated chains and rigid spacers

Abstract In the aim to produce superhydrophobic surface properties, the nanofibers are excellent candidates due to the possible control in the water adhesion by the nanofiber characteristics, for example. Here, we report the growth of nanofibers with various assemblies directly on surfaces by electropolymerization. For this purpose, an original 3,4-ethylenediothiophene monomer was synthesized. The monomer contains a short fluorinated chain (C 4 F 9 ) in order to preserve the nanofiber morphology and a highly rigid methoxybenzothioate spacer for the reduction of the mobility. In this work, we show that various nanofibrous structures and superhydrophobic properties can be obtained by modifying the electrolyte while the surface roughness can also be controlled by the number of deposition scans. The nanofibrous polymers could be used to control the attachment and growth of cells or bacteria.

Electropolymerized phenol derivatives as permselective polymers for biosensor applications.

Amperometric biosensors are often coated with a polymeric permselective film to avoid electroactive interference by reducing agents present in the target medium. Phenylenediamine and phenol monomers are commonly used to form these permselective films in the design of microsensors and biosensors. This paper aims to evaluate the permselectivity, stability and lifetime of polymers electrosynthesized using either constant potential amperometry (CPA) or cyclic voltammetry (CV) from naturally occurring phenylpropanoids in monomeric and dimeric forms (eugenol, isoeugenol, dehydrodieugenol and magnolol). Sensors were characterized by scanning electron microscopy and permselectivity analysis. Magnolol formed an electro-deposited polymer with a more defined three-dimensional texture in comparison with the other films. The phenol-derived films showed different permselectivity towards H2O2 over ascorbic acid and dopamine, likely to be related to the thickness and compactness of the polymer. The CV-derived films had a better permselectivity compared to the CPA-corresponding polymers. Based on these results, the permselectivity, stability and lifetime of a biosensor for glucose were studied when a magnolol coating was electro-deposited. The structural principles governing the permselectivity of the magnolol-derived film are suggested to be mainly related to the conformational flexibility of this monomer. Newly designed biosensors, coated with electropolymerized natural phenol derivatives, may represent promising analytical devices for different application fields.

Development of Amperometric Glucose Biosensor Based on Prussian Blue Functionlized TiO2 Nanotube Arrays

Amperometric biosensors consisting of oxidase and peroxidase have attracted great attention because of their wide application. The current work demonstrates a novel approach to construct an enzymatic biosensor based on TiO2 nanotube arrays (TiNTs) as a supporting electrode on which Prussian Blue (PB)-an “artificial enzyme peroxidase” and enzyme glucose oxidase (GOx) have been immobilized. For this, PB nanocrystals are deposited onto the nanotube wall photocatalytically using the intrinsic photocatalytical property of TiO2, and the GOx/AuNPs nanobiocomposites are subsequently immobilized into the nanotubes via the electrodeposition of polymer. The resulting electrode exhibits a fast response, wide linear range, and good stability for glucose sensing. The sensitivity of the sensor is as high as 248 mA M−1 cm−2, and the detection limit is about 3.2 μM. These findings demonstrate a promising strategy to integrate enzymes and TiNTs, which could provide an analytical access to a large group of enzymes for bioelectrochemical applications including biosensors and biofuel cells.

Multielectrochromism of redox states of thin electropolymerised films of poly(3-dodecylpyrrole) involving a black coloured state

Abstract Thin films of poly(3-dodecylpyrrole) have been found to yield multi-electrochromic characteristics. Optimisation of the polymer electrodeposition process enabled fabrication of layers exhibiting three distinct colourations at different oxidation levels. Coupled EPR-UV-Vis-NIR spectroelectrochemistry enabled correlation of these colour changes with the formation and decay of polaron and bipolaron charge carriers, offering an insight into the mechanism of doping/dedoping processes taking place in this polymer. The ionisation potential of the polymer was found to be very low, with valence band edge located at -3.7 eV, explaining the relative oxidation ease of the polymer and accounting for an ample number of spins present in the electrochemically dedoped polymer film. Maximum optical contrast of up to 15% and a visible light range averaged one of 10% was observed. Dynamic colour switching contrast of 10% is attainable at 5 s switching time, while switching steps as short as 0.5 s afford 6% contrast value. The fully oxidised polymer features broad UV-Vis absorption, making the system an interesting candidate for transmissive-to-black electrochromic devices.