Self-Assembly of Molybdophosphate on a Glassy Carbon Electrode Covalently Modified with Choline and Electrocatalytic Reduction of Iodate

Abstract

Choline can be covalently grafted on glassy carbon electrodes using cyclic voltammetric method, forming a stable cationic monolayer-modified electrode (Ch/GCE). Keggin-type molybdophosphate anions, α-PMo₁₂O₄₀^3-, then were self-assembled on the Ch/GCE through electrostatic interactions for fabrication of an electrochemical sensor, which is denoted as α-PMo₁₂/Ch/GCE. This two-layer modified electrode was carefully characterized by cyclic voltammetry and X-ray photoelectron spectroscopy. It was found that the sensor exhibits strong electrocatalytic activity and sensitivity toward the reduction of IO₃^-. The content of IO₃^- in a table salt was determined with satisfactory results. The sensor is promising as an electrochemical sensor for the detection of IO₃^-.