石墨烯/纳米金增敏分子印迹电化学传感器检测草甘膦

In this paper, graphene (RGO) and RGO/AuNPs was prepared to modify the surface of glassy carbon electrode. Using pyrrole as the functional monomer and glyphosate as the template molecule, a molecular imprinted electrochemical sensor with high sensitivity to glyphosate was prepared by electrochemical polymerization. Different kinds of modified electrodes have been characterized. The principle of molecular imprinting, the method of template removal, the ratio of the template to the functional monomer, and the effect of the nano-materials on molecular imprinting were investigated. Results show that when the molar ratio of glyphosate and pyrrole was 1:8 and the electrochemical elution solution was 0.01 M NaOH, the molecularly imprinted sensor based on RGO/AuNPs modified glassy carbon electrode showed the best performance. In the detection system of pH 4.0 and enrichment time of 30 min, glyphosate concentration at the range of 5-800 ng/mL displayed a linear relation with the corresponding current changes in the peak of potassium ferricyanide oxidation, and the detection limit (S/N=3) was 0.50 ng/mL. Overall, the glyphosate molecularly imprinted sensor had a strong specificity recognition and the method has good stability and reproducibility.