Non-enzymatic glucose detection free of ascorbic acid interference using nickel powder and nafion sol-gel dispersed renewable carbon ceramic electrode

A new enzymeless glucose sensor has been fabricated by a nickel powder dispersed sol-gel derived ceramic graphite composite. The electrocatalytic oxidation of glucose in alkaline medium directly at nickel powder modified carbon ceramic electrode has been investigated. The modified electrode offer excellent electrocatalytic activity toward the glucose oxidation at low positive potential (0.45 V vs. Ag/AgCl, 3 M KCl). Glucose was determined chronoamperometrically at the surface of the modified electrode in pH 13. Under the optimized condition, the calibration curve is linear in the concentration range of 0.5-5000 μM. The detection limit (signal-to-noise 3) and sensitivity are 0.1 μM and 40 nA μM−1, respectively. The glucose sensor can be renewed easily in a reproducible manner by a simple polishing step and it has a long operational lifetime and short response time t90% < 1 s. In addition, the fabrication of CCE with nafion and nickel powder was employed to eliminate the interference of ascorbic acid during the catalytic oxidation of glucose. The capability of the modified electrode for direct glucose quantification in human blood serum matrix is also discussed.