Capacitive detection of glucose using molecularly imprinted polymers

A novel glucose biosensor based on capacitive detection has been developed using molecularly imprinted polymers. The sensitive layer was prepared by e lectropolymerization of o-phenylenediamine on a gold electrode in the prese nce of the template (glucose). Cyclic voltammetry and capacitive measuremen ts monitored the process of electropolymerization. Surface uncovered areas were plugged with 1-dodecanethiol to make the layer dense, and the insulati ng properties of the layer were studied in the presence of redox couples. T he template molecules and the nonbound thiol were removed from the modified electrode surface by washing with distilled water. A capacitance decrease could be obtained after injection of glucose. The electrode constructed sim ilarly but with ascorbic acid or fructose only showed a small response comp ared with glucose. The stability and reproducibility of the biosensor were also investigated. (C) 2001 Elsevier Science B.V. All rights reserved.