Use of polydimethylsiloxane for constructing amperometric glucose-sensing enzyme electrode with low interference level

Glucose-sensing electrodes based on the cathodic detection of oxygen consum ption through the glucose oxidase (GOx) reaction were constructed by using polydimethylsiloxane (PDMS). One electrode, a PDMS/GOx-bilayer electrode wa s fabricated by placing an enzyme layer on a PDMS-coated electrode, which w as prepared by dip-coating from an aqueous dispersion of the siloxane polym er. Another enzyme electrode, an electrode with a PDMS layer containing lip id-modified GOx. was prepared by placing aqueous dispersions of the polymer and the modified enzyme on the base electrode surface and drying. The elec trode using modified GOx could easily be prepared and suitable for measurin g glucose in high concentrations (around 5 mM), compared to the bilayer-bas ed system. On the other hand, both the electrodes could be used for the sel ective determination of glucose: the permselectivity of PDMS made it possib le to monitor the oxygen consumption rate without serious electrochemical i nterferences.