Platinization of shapable electroconductive polymer film for an improved glucose sensor

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 H2O2 oxidation current at a lower applied potential. Glucose sensors were prepared by adsorbing glucose oxi dase 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 degrees 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/cm(2)) 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.