Imprinted sol–gel electrochemical sensor for melamine direct recognition and detection

A sol–gel based electrochemical sensor was developed for melamine (Mel) direct and selective detection in real samples. Thin film of molecularly imprinted sol–gel polymers with specific binding sites for Mel was fabricated on glassy carbon electrode surface by electropolymerization method. Oxidation peak of Mel was chosen as a detected signal for the properties study of the sensor. The molecularly imprinted polymers film modified method, electropolymerization scan rate, scan cycles, potential range, amount of Mel and extraction conditions for sensor preparation were optimized. Under the optimized conditions, the sensor displayed an excellent recognition capacity towards Mel compared with other structural similar molecules. With acceptable regeneration and stability the sensor could detect Mel in the range of 6.3 × 10−7–1.1 × 10−4 mol L−1 with a detected limit of 6.8 × 10−8 mol L−1 (S/N = 3). The result of real samples detection indicated that the proposed low cost electrochemical sensor might be potential to determine Mel in real samples to ensure food safety.