Development of an amperometric sulfite biosensor based on SOx/PBNPs/PPY modified ITO electrode

► Development of sulfite biosensor based on SOx/PBNPs/PPY/ITO electrode. ► Biosensor showed optimum response within 2 s, at 20 mV s−1, pH 8.5 and 35 °C. ► Linear range and detection limit were 0.5-1000 μM and 0.12 μM. ► Biosensor measured sulfite in red and white wine samples. ► Electrode used 200 times over a period of 100 days when stored at 4 °C.