Application of unusual on/off electrochemical properties of a molecularly imprinted polymer based on an EDOT-thiophene precursor for the detection of ephedrine

Electrocopolymerization of bithiophene with a monomer combining an EDOT moiety with a thiophene ring on which a carboxylic group is attached at the internal β-position via a sulphide linkage (1) has been investigated with the aim of producing a molecularly imprinted polymer. Analysis of the electrochemical behaviour of the film grown under various conditions shows that potentiostatic electrocopolymerization leads to a polymer which can detect ephedrine via an unusual on/off switching of the electrochemical properties of the film in the presence of the target molecule.