Chemosensor devices: voltammetric molecular recognition at solid interfaces

Abstract

This article reviews progress in modifying electrode surfaces with functional organic molecules which act as signalling units upon molecular recognition of a guest molecule or ion. This process triggers a change in the physicochemical properties of the host assembly which can be monitored by an electrochemical response. Topics covered include: molecular recognition in conjugated polymers; molecular recognition in monolayers formed by Langmuir-Blodgett and self assembly techniques; incorporation of recognition sites (‘molecular gates’) in otherwise passivating monolayers; ion channel sensors. Representative redox moieties include: polythiophene and polypyrrole derivatives, paraquat, ferrocene, tetrathiafulvalene, metalloporphyrins, C 60 , Ru(NH 3 ) 6 3+ and Fe(bpy) 2 (CN) 2 0 . Issues relevant to the development of practical, commercially-viable sensors are considered.