Determination of hydrogen peroxide, glucose and hypoxanthine using (bio) sensors based on ruthenium dioxide-modified screen-printed electrodes

Screen-printed electrodes modified with ruthenium dioxide were investigated as amperometric sensors for the determination of hydrogen peroxide using flow injection analysis (FIA). With additions of enzymes (glucose oxidase or xanthine oxidase) immobilized onto the electrode surface via Nafion films, corresponding biosensors for the quantification of glucose or hypoxanthine were developed. Factors influencing their amperometric responses (operational potential, flow rate, pH of the phosphate buffer carrier) were studied in detail. Applications in food analysis were also examined.