Preparation of Molecularly Imprinted Electrochemiluminescence Sensor and Its Application for Determination of Kanamycin

A glass carbon electrode (GCE) modified with a composite of CdS quantum dots and chitosan (CdS-CS) was prepared, and the modified electrode was denoted as CdS-CS/GCE. Kanamycin was used as the template molecule and 3-aminophenylboronic acid (APBA) was used as the functional monomer. Molecularly imprinted polymer (MIP) membrane was prepared with electropolymerization on the surface of the modified electrode by cyclic voltammetry (CV). The constructed sensor was denoted as MIP/CdS-CS/GCE. Kanamycin could specifically bind to the MIP on the sensor surface and occupy the imprinting hole.Therefore, kanamycin could block the diffusion of K₂S₂O₈ as a co-reactant to the electrode surface and reduce the electrochemiluminescence intensity. The difference ΔI (ΔI=I₀-I) between the electrochemiluminescence intensity (I₀) of the sensor in blank solution and the electrochemiluminescence intensity (I) of the sensor in kanamycin standard solution was used as response signal. Under the optimized experimental conditions, linear relationship between the response signal ΔI and the logarithm values of kanamycin concentration was found in the range of 1.0×10^-11-1.0×10^-7mol·L^-1, and the correlation coefficient was 0.999 0. The detection limit (3S/N) was 5×10^-12mol·L^-1. Test for recovery was made by standard addition method on the actual sample, giving results in the range of 99.9%-103%, with RSDs (n=5) of the determined values in the range of 2.5%-4.3%.