A Electrochemical Sensor for Melamine Detection Based on Copper-Melamine Complex Using OMC Modified Glassy Carbon Electrode

A simple sensor ordered mesoporous carbon/glassy carbon electrode (OMC/GCE) is developed in this paper for melamine (Mel) detection, which is based on conversion of Mel from non-electroactive Mel to electroactive Cu-Mel complex under presence of copper ions in 0.1 M pH 9.0 borate buffer containing 20% methanol (v/v) as supporting electrolyte at the surface of OMC modified electrode. Fourier transform infrared (FT-IR) spectra demonstrate that Mel interact with copper ions to form a complex through coordinate bond interaction. Surface feature of modified electrode was characterized by cyclic voltammetry (CV). Several important parameters controlling performance of the sensor were investigated and optimized. In optimal conditions, the anodic peak of Cu-Mel complex is linear with concentration of Mel ranging from 1.0 × 10−8 to 5.0 × 10−7 M and 5.0 × 10−7 to 2.0 × 10−5 M, with limit of detection (LOD) (based on S/N = 3) of 2.0 × 10−9 M for Mel. This sensor was successfully applied to determination of Mel in milk products.