A POTENTIOMETRIC POLYPYRROLE-BASED GLUCOSE BIOSENSOR

A new concept is described for monitoring a biomolecule with a sensor having an enzyme entrapped in a conducting polymer. This is based on t he sensitivity of the electroactive polymer itself to changes of pH in solution. The concept has been investigated for a glucose sensor with glucose oxidase (GOD) immobilized in a polypyrrole (PPy) layer on an inert platinum electrode. Measurements with a Pt/PPy/GOD electrode for glucose concentrations in the physiological range gave a linear corre lation with logarithm of concentration over one decade with a satisfac tory dynamic response. There was practically no change of slope or ran ge of linear response to glucose after several days of use; this was i n contrast to the amperometric response of the detector when there was about a 50% loss of sensitivity.