Amperometric Sulfite Sensor Using Electrodecorated Pt Particles onto an Aminated Glassy Carbon Electrode Prepared by Stepwise Electrolysis

Abstract

A novel modified glassy carbon electrode with platinum (Pt)-electrodecorated and nitrogen-containing functional groups was prepared by a stepwise electrolysis. The prepared electrode exhibited an electrocatalytic activity towards sulfite oxidation that was better than that of a bare glassy carbon electrode. The electrocatalytic activity of sulfite oxidation has been applied to an amperometric sulfite sensor. A favorable linear relationship between the current response (ΔI) and the sulfite concentration up to 500 M was exhibited. The detection limit was estimated to be 3 µM based on the criterion of signal-to-noise (S/N) ratio of 3 under optimized conditions. In regards to the reproducibility, the RSD (n= 10) was 8.9% for 80 µM sulfite.