Platinization of Shapable Electroconductive Polymer Film for an Improved Glucose Sensor

Abstract

This paper describes a novel electrode material for the preparation of a first generation amperometric biosensor. The material consists of a flexible conductive polymer film of polypyrrole doped with polyanions and a layer of microporous Pt black, prepared electrochemically on the polymer film. Sensors fabricated with this material produce a comparatively higher oxidation current at a lower applied potential. Glucose sensors were prepared by adsorbing glucose oxidase at the porous Pt black structure, covering with gelatin, and finally cross‐linking with glutaraldehyde at dry condition. The developed sensors showed significantly improved performance over similar reported sensor systems. The performance of the glucose sensor was evaluated by a specially designed flow injection analysis (FIA) system. The sensors were continuously polarized at 25°C and glucose samples were automatically injected at 30 min intervals. The sensors worked at 0.3 to 0.4 V and produced a huge current response (>1 mA/cm² with a wide linear range of detection (0 to 100 mM). The system effectively recycles oxygen, thus, the response current was not affected by a variation of oxygen concentration of the buffer. The interference of ascorbic acid, uric acid, bilirubin, etc. (at a physiological level) produced a current within the experimental error level. The sensor showed an extended working and shelf life.