Free-standing oligo(oxyethylene)-functionalized polythiophene with the 3,4-ethylenedioxythiophene building block: electrosynthesis, electrochromic and thermoelectric properties

The effect of copolymerization and carbon nanoelements on the performance of poly(2,5-di(thienyl)pyrrole) biosensors

The development of biosensing interfaces based on copolymerization of benzenamine-2,5-di(thienyl)pyrrole (SNS-An) with 3,4-ethylenedioxythiophene (EDOT) is reported. Both homopolymer P(SNS-An) and copolymer P(SNS-An-co-EDOT) films were prepared and evaluated, in terms of biosensing efficiency, upon incorporation of carbon nanoelements (carbon nanotubes and fullerene) and cross-linking of glucose oxidase. The copolymer revealed superior performance as a biosensing interface as compared to the homopolymer structure or previously reported P(SNS) biosensors. The analytical characteristics and stability studies were performed both at cathodic potential, monitoring O₂ consumption, as a result of catalytic reaction of glucose oxidase towards glucose and at anodic potential, following the oxidation of the H₂O₂ produced during the catalytic reaction. Whilst the measurements on the positive side offered an extended linear range (0.01-5.0 mM), the negative side provided sensitivity up to 104.96 μA/mMcm^-1 within a shorter range. Detection limits were as low as 1.9 μM with Km value of 0.49 mM. Lastly, the most performant biosensing platforms, including copolymeric structure and CNTs were employed for analysis in real samples.

Functionalized Poly(3,4-ethylenedioxy bithiophene) Films for Tuning Electrochromic and Thermoelectric Properties

Conductive thiophene-based polymers have garnered great attention for use in organic electron materials such as electrochromic and thermoelectric materials. However, they suffer from poor electron transport properties and long-term stability, leading to limited development eventually. Here, we proposed a strategy of functionalized thiophene-based polymers with oligo(ethylene glycol) or alkyl side chains and synthesized a series of poly(3,4-ethylenedioxy bithiophene)s (PEDTs) to tune their electrochromic and thermoelectric properties. An alkyl group bearing electronic ability at the thiophene ring effectively achieved a large increase in the electrical conductivity with nearly invariable Seebeck coefficient, resulting in an enhancement by 1 order of magnitude for the thermoelectric power factor. Moreover, the electrochromic properties of functionalized PEDTs gained an effective improvement in the optical contrast and coloration efficiency as well as stability with multicolor changes between neutral and oxidized states. The functionalized PEDTs can be proposed as an alternative strategy to tune the electrochromic and thermoelectric properties for organic polymer materials.