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 O-2 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 mu A/mMcm(-1) within a shorter range. Detection limits were as low as 1.9 mu M 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.