Redox-active conducting polymers incorporating ferrocenes. Preparation, characterization and bio-sensing properties of ferrocenylpropyl and -butyl polypyrroles

Abstract

The multi-step synthesis of the novel ferrocene-substituted pyrrole monomers, N-(3-ferrocenylpropyl)pyrrole ( 1), and 3-(4-ferrocenylbutyl)pyrrole ( 2), have been studied and optimized. A single crystal X-ray structure analysis has been performed on the synthetic intermediate 3-(4-ferrocenylbutyl)- N-(triisopropylsilyl)pyrrole. Monomers 1 and 2 can be electropolymerized to form the homopolymer, poly- 2, and the copolymers, pyrrole- co- 1 and pyrrole- co- 2. The polymers have been characterized using cyclic voltammetry, UV–visible spectroscopy, scanning electron microscopy (SEM) and four-point probe conductivity measurements. The use of pyrrole- co- 1 coatings for quantitative sensing and determination of the redox-active enzyme cytochrome C in solution has been demonstrated.