The poly(o-anisidine)–sulfuric acid–glucose oxidase (POA–H2SO4–GOx) electrode has been investigated in the present work. Platinum electrode was used for the synthesis of poly (o-anisidine)–sulfuric acid (POA–H2SO4) film using galvanostatic method with 0.2 M o-anisidine, 1.0 M H2SO4 solution, 1.0 pH and 2 mA/cm2 applied current density. The synthesized film was characterized using electrochemical technique, conductivity measurement, UV–visible spectroscopy, Fourier transform infrared spectroscopy, and scanning electron microscopy. GOX was immobilized on synthesized POA–H2SO4 film by cross-linking via glutaraldehyde in phosphate and acetate buffer. The Michaelis–Menten constant (