基于纳米Nb_2O_5/石墨烯复合材料的增强效应电化学测定绿原酸

Electrochemical Detection of Chlorogenic Acid Based on the Enhancement Effect of Nb_2O_5/RGO Nanocomposites

制备了Nb_2O_5/石墨烯修饰玻碳电极(Nb_2O_5/RGO/GCE),建立了一种简便、灵敏检测绿原酸的电化学方法。用氧化石墨烯(GO)和五氯化铌(Nb Cl5)一步溶剂热法制备Nb_2O_5/RGO复合材料,并用扫描电子显微镜(SEM)对其进行形貌表征。采用循环伏安法(CV)和方波伏安法(SWV)研究了绿原酸在Nb_2O_5/RGO/GCE上的电化学行为。结果发现,Nb_2O_5/RGO复合材料能显著增强绿原酸的电化学活性。对实验条件(如pH值、扫描速率与富集时间等)进行了优化。在最佳条件下,绿原酸的氧化峰电流与浓度在5.0×10^(-7)~1.2×10^(-5)mol/L范围内呈良好的线性关系,检出限为2.0×10^(-7)mol/L。采用修饰电极测定各种药物中绿原酸的含量,得到加标回收率为96.6%~101.5%。该方法具有良好的灵敏度和稳定性,已成功应用于药物中绿原酸含量的测定。

A simple and sensitive electrochemical method was developed for the determination of chlorogenic acid based on Nb2O5/reduced graphene oxide（RGO） nanocomposites modified glassy carbon electrode（Nb2O5/RGO/GCE）.Nb2O5/RGO composite was synthesized by a hydrothermal reduction using NbCl5 and graphene oxide（GO）,and its morphology was characterized by scanning electronic microscopy（SEM）.Electrochemical behaviors of chlorogenic acid on Nb2O5/RGO/GCE were studied by cyclic voltammetry（CV） and square wave voltammetric（SWV） methods.The results showed that the Nb2O5/RGO composite displayed a remarkably enhanced electrochemical activity toward the oxidation of chlorogenic acid.Conditions influencing the detection process,such as pH value of buffer solution,scan rate and accumulation time,were optimized.Under the optimized conditions, the oxidation peak current of chlorogenic acid has a good linear relationship with concentration of chlorogenic acid in the range of 5.0×10^-7-1.2×10^-5mol/L,with a detection limit（S/N=3） of 2.0×10^-7mol/L.The proposed method was applied in the determination of chlorogenic acid in pharmaceutical products,and the spiked recoveries were in the range of 96.6%-101.5%.With good sensitivity and stability,the developed method was successfully applied in the determination of chlorogenic acid in pharmaceutical products.