Ordered mesoporous carbon as electrode modification material for selective and sensitive electrochemical sensing of melamine

A selective and sensitive electrochemical method has been developed to determine the melamine in milk samples by using ordered mesoporous carbon (OMC) as electrode modification material, based on the oxidation of non-electroactive melamine monomers to electroactive dimers. OMC–Nafion modified glassy carbon electrode (OMC–Nafion/GCE) showed more favorable electron transfer kinetics as well as stronger and more stable electrocatalytic response toward melamine, from comparison to multiwall carbon nanotubes modified GCE (MWCNTs–Nafion/GCE). Under optimal experimental conditions, the OMC–Nafion/GCE electrode offered highly sensitive and rapid response to Mel at the potential of 0.7 V for saturated calomel electrode in 0.5 M H2SO4. The linear range of Mel concentration was from 5 × 10−8 to 7 × 10−6 M with a correlation coefficient of 0.999, and the detection limit was 2.4 × 10−9 M (S/N = 3). The OMC–Nafion/GCE sensor was successfully applied to the determination of Mel in milk product and showed high selectivity, sensitivity, and reproducibility.