基于纳米金复合物的电化学传感器检测果汁中多菌灵

Detection of Carbendazim in Fruit Juices Based on Nano-Gold Nanocomposite Electrochemical Sensor

目的:建立纳米金复合物的电化学传感器检测果汁中多菌灵。方法:利用甘氨酸功能化石墨烯量子点作为还原剂和稳定剂,快速合成金-甘氨酸功能化石墨烯量子点(Au-Gly-GQD)复合物。Au-Gly-GQD修饰的玻碳电极与多菌灵适配体之间通过Au-S键结合,然后利用适配体与多菌灵之间的特异性识别实现对多菌灵的检测。结果:边缘带有丰富基团的Gly-GQD与金纳米粒子作用,显著提高了金纳米粒子的分散性和稳定性。与金纳米粒子相比,Gly-GQD与金纳米粒子的结合表现出更高的电催化活性。在最佳条件下,多菌灵浓度在0.005~100.000pmol/L范围内,产生的DPV峰电流与多菌灵浓度的负对数呈良好的线性关系,相关系数(r^(2))为0.998,检出限达到0.004 pmol/L。结论:通过纳米金复合物的高催化活性,建立了果汁中多菌灵的电化学检测方法。该方法表现出较高的灵敏度和选择性。

Objective:To establish an electrochemical sensor for the detection of carbendazim in fruit juices with nano-gold composite.Methods:Gold-glycine-functionalized graphene quantum dots hybrid(Au-Gly-GQD)were rapidly prepared using glycine-functionalized graphene quantum dots as reducing agent and stabilizer.The Au-Gly-GQD-modified glassy carbon electrode was bound to the carbendazim aptamer by Au-S bond,and then the detection of carbendazim is realized by the specific recognition between the aptamer and carbendazim.Results:Gly-GQD with rich groups on the edge interacts with gold nanoparticles,which significantly improves the dispersion and stability of gold nanoparticles.Compared with gold nanoparticles,Gly-GQD combined with gold nanoparticles showed higher electrocatalytic activity.Under the optimal conditions,when the concentration of carbendazim was 0.005-100.000 pmol/L,the generated DPV peak current had a good linear relationship with the negative logarithm of the concentration of carbendazim.The correlation coefficient(r^(2))was 0.998,and the limit of detection reached 0.004 pmol/L.Conclusion:An electrochemical method for the determination of carbendazim in fruit juices is established based on the high catalytic activity of nano-gold nanocomposite.This method shows high sensitivity and selectivity.