Melamine Molecular Imprinting Electrochemical Sensor: Research and Development

Molecularly imprinted films(MIP)were prepared in pH 6.80 PBS buffer solution by cyclic voltammetric electropolymerization method on glassy carbon electrode with o-aminophenol acting as monomer and melamine acting as imprinted molecules.Melamine molecularly imprinted electrochemical sensor was obtained after removing imprinted molecules-melamine from the films.The significant differences in electrochemical signals of the sensors were observed between before and after removal of imprinted molecules.The response characteristic of the MIP sensor was studied by differential pulse voltammetry(DPV) using K3 [Fe(CN)6 ] as probe.The concentrate of melamine in the respective range of 0.4-1.0μg /L and 2.0-10μg /L presented excellent linear relationship to its change in peak currents(Δi) and its linear regression equation are Δi =0.2812c-0.1059,R=0.997 andΔi =0.01341c+0.1735,R=0.999 respectively.The limit of quantification was 0.4μg/kg and the response time was about 5min.The relative standard deviation of the sensor for determination of melamine was 3.46%(n = 7) with good selectivity.It was applied in determination of melamine in milk and milk powder samples,and the spiked recoveries were 88.3% to 110%.