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Conductive Electroactive Polymers in Electrocatalysis and Sensing Applications
Published in Inamuddin, Mohd Imran Ahamed, Rajender Boddula, Adil A. Gobouri, Electroactive Polymeric Materials, 2022
Achi Fethi, Benmoussa Fateh, Henni Abdellah, Zembouai Idris, Kaci Mustapha
Electropolymerization can be defined as an electrochemical process for manufacturing a polymer film on a substrate, which is composed of a working electrode, from a solution that contains the monomer, the solvent, and the supporting electrolyte. These will be incorporated into the polymer during the process as a dopant ion. Electrochemical syntheses are carried out in aqueous or organic solvents, using assemblies with three electrodes: a working electrode that oxidizes the polymer; a reference electrode to control; and a counter electrode that allows the passage of current (Figure 9.1(a)). The electropolymerization process involves the transfer of electrons, in either direction, between the substrate and the monomer in solution (Berkes, Bandarenka, and Inzelt, 2015). It is the charged monomer that then allows the polymerization reaction to take place.
Major Classes of Conjugated Polymers and Synthetic Strategies
Published in Sam-Shajing Sun, Larry R. Dalton, Introduction to Organic Electronic and Optoelectronic Materials and Devices, 2016
Electrochemical polymerization is a main method for the preparation of conducting polymer films, especially for the preparation of PPy. The electrochemical approach has the advantage of one-step production of conducting polymer films onto a metal electrode surface. Moreover, the properties of the conducting polymer films produced electrochemically can be modulated easily by changing the counter anions in the electrolyte solutions, and the thickness of the conducting polymer films can be precisely controlled by controlling the charge amount of the electropolymerization. In addition, electropolymerization is also very important in the preparation of polymer modified electrode, enzyme electrode immobilized by conducting polymers, polymer electrode for electrochromic displays, etc.
Toward Understanding the Intelligent Properties of Biological Macromolecules
Published in George K. Knopf, Amarjeet S. Bassi, Smart Biosensor Technology, 2018
There are distinct advantages that electrochemical methods provide over other signal transduction methodologies for use in biosensors. One advantage is electrochemical control over the electrode potential and therefore selectivity over the analyte species to be quantitated, typically by the current detected at the electrode. Another is that electrochemical sensing via potential control is confined to the electrode surface, and the electrode itself may be whatever geometry and size is required, including microscale to nanoscale dimensions. As a result, electrochemical methods are an attractive methodology for creating biosensors. They provide an additional advantage in that electropolymerization is possible upon an electrode, allowing the creation of thin polymeric films from monomers in solution through controlled electron transfer. Such films can be utilized for both immobilization of biological elements as well as the underlying signal transduction process of the biosensor, where electron transfer can be employed to generate a signal dependent upon analyte concentration. Electrochemical-based biosensors were some of the earliest types of biosensors commercialized (52,53). A good example is the glucose sensor developed for monitoring blood glucose levels in diabetic and prediabetic patients. At the Center for Intelligent Biomaterials, we have carried out basic studies of the electropolymerization of thin films, as well as employing strategies utilizing these films and electrochemical signal transduction in a number of studies of different biosensor systems. We describe some of these systems in the following sections.
A novel electrochemical glucose biosensor based on a poly (L-aspartic acid)-modified carbon-paste electrode
Published in Preparative Biochemistry & Biotechnology, 2020
Electropolymerization represents a promising means by which to modify the surfaces of electrodes due to its sensitivity and selectivity to analytes, its ability to provide larger surface, its ability to promote electron transfer rate, and strong adherence of the polymer to the electrode’s surface.[7,8] Recently, the electropolymerization of amino acids has become increasingly important, as they can form their own functional groups and biocompatible electroactive polymers.[9,10] Aspartic acid, which has a free carboxylic acid group, can easily be electropolymerized on the surface of an electrode. Although no prior studies have investigated electrochemical glucose biosensors based on polyaspartic-acid-coated surfaces, researchers have examined other biosensor applications. For example, Wang et al. developed a polyaspartic-acid film-based sensor for the detection of catechin in tea drinks.[11] A poly(L-aspartic-acid)-modified glassy carbon electrode was developed by Yu et al. for the determination of epinephrine.[12] Additionally, Donmez et al. fabricated a nucleic acid biosensor for the detection of the hepatitis C virus genotype 1a based on a poly(L-aspartic acid)-modified pencil-graphite electrode.[13]
Thermoelectric materials and applications for energy harvesting power generation
Published in Science and Technology of Advanced Materials, 2018
Ioannis Petsagkourakis, Klas Tybrandt, Xavier Crispin, Isao Ohkubo, Norifusa Satoh, Takao Mori
All the aforementioned works involve a tuning of the doping levels with a conventional chemical redox reaction. An alternative approach for doping optimization is through electrochemical methods, which offer a better control for fine-tuning the doping levels by changing the electrochemical potential of the polymer and measuring a current corresponding to the amount of doping charges. A typical electrochemical setup is presented in Figure 5(a). Park et al. [35] optimized the doping levels of PEDOT:Tos to a record power factor of 1270 μW/m∙K2 (Figure 5(b)). Another use of electrochemical optimization was reported by Bubnova et al. [36] where an organic electrochemical transistor (Figure 5(c)) was used to optimize the thermoelectric properties of PEDOT:PSS. In such a device, the power factor was optimized by applying a gate voltage in the configuration (Figure 5(d)). Electrochemistry can also be used to directly polymerize conducting polymers through electropolymerization. Parameters such as temperature, current density, frequency, electrolyte, counterions (e.g. Zhang et al. [37] uses sulfated poly(β-hydroxyethers) counterions for PEDOT) can be used to modify the morphology and film properties. Culebras et al. [38] published a report on electropolymerized PEDOT with conductivity of ~ 1000 S/cm and an optimized figure of merit of 0.22 at room temperature.
Recent advances in the synthesis of and sensing applications for metal-organic framework-molecularly imprinted polymer (MOF-MIP) composites
Published in Critical Reviews in Environmental Science and Technology, 2023
Yongbiao Hua, Deepak Kukkar, Richard J. C. Brown, Ki-Hyun Kim
In general principle, electropolymerization involves synthesizing a polymer onto the surface of a solid electrode material or supporting substrate by applying a suitable potential or range of potentials (Gui et al., 2019; Lahcen & Amine, 2019). Recently, the electropolymerization method has been used to synthesize MOF-MIP composites (e.g., Co-MOF/MIP (Yahyapour et al., 2021), Zr-MOF/MIP (Malekzadeh et al., 2020), and MMOF-MIP (Wei et al., 2017)). The Zr-MOF/MIP was made with a mixture of diclofenac (DFC, template) and para-aminobenzoic acid (functional monomer) in phosphate buffer solution (PBS). The reaction mixture was subjected to cyclic voltammetry (CV) (−1 V to + 1.5 V with a Ag/AgCl reference electrode at a rate of 50 mV/s for 15 cycles) to produce a Zr-MOF/MIP thin film on a glassy carbon electrode (GCE) surface (Malekzadeh et al., 2020). Similarly, Co-MOF/MIP/GCE using 0.5 mM ciprofloxacin (CIP) as the template and 5 mM 4-aminobezoic acid as the functional monomer in PBS was prepared over a GCE surface by electropolymerization with 50 mV/s for 15 scans in the range of −0.5 to + 1.5 V (Ag/AgCl reference electrode) (Yahyapour et al., 2021). After the CIP was removed with sodium sulfate (0.2 mol/L), Co-MOF/MIP/GCE was obtained to detect CIP species (Yahyapour et al., 2021). In another study, MIP-MIL was also fabricated using an electropolymerization method (An et al., 2019). The synthesis was carried out by mixing MIL-53(Fe) powder with MAA and melamine (template) in PBS, followed by electropolymerization. The reaction conditions were optimized by varying the molar ratio of melamine to MAA (3:1, 2:1, 1:1, 1:2, and 1:3), the PBS pH (5.0–7.0), number of scan cycles (15–35), and scan rate (40–160 mV/s). The resulting MIP membrane was attached to the rough surface of MIL-53 (Fe), as shown in Figure 5(a) (An et al., 2019).