Immobilization of GOD on electrochemically synthesized Ppy–PVS composite film by cross-linking via glutaraldehyde for determination of glucose

Abstract

The Ppy–PVS-GOD biosensor for determination of glucose has been described. The enzyme, glucose oxidase (GOD) was immobilised by cross-linking via glutaraldehyde on a polypyrrole–polyvinyl sulphonate (Ppy–PVS) composite film. The Ppy–PVS film was electrochemically synthesized on indium–tin-oxide (ITO)-coated glass plate. We have synthesized Ppy–PVS film with 0.1 M pyrrole, 0.025 M PVS at 3.0 pH and 1 mA/cm 2 current density. The immobilization was done by cross-linking 2 mg/ml GOD via 0.1% glutaraldehyde at 0.1 M phosphate buffer with 7.0 pH. The synthesized composite films were characterized using galvanostatic electrochemical technique, electrical conductivity, UV–Vis spectroscopy, Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). The cross-linking of enzyme and porous morphology of the polymer film leads to high enzyme loading and an increase in lifetime, stability and fast response time of the enzyme electrode. Amperometric response was measured as a function of different concentration of glucose. It was observed that current increases with increasing glucose concentration in the range 1–50 mM.