Ag@C核壳纳米结构的制备及其对双酚A的敏感特性

Preparation of Ag@C Core-Shell Nanostructure and Its Sensitivity to Bisphenol A

采用水热合成法,通过改变反应时间制备了一系列碳包覆银纳米粒子的Ag@C核壳纳米结构,并用其修饰丝网印刷电极制备测定双酚A (BPA)的高灵敏电化学传感器。扫描电子显微镜(SEM)结果显示,Ag@C核壳结构呈均匀的球形,每个微球内含有一个直径约80 nm的Ag粒子;随水热反应时间延长,Ag@C微球的碳壳厚度和直径均增大;循环伏安(CV)测试结果表明,Ag@C结构对BPA的氧化有显著的催化作用;水热反应时间为4 h所制备的Ag@C-3,因其碳壳厚度适当,对BPA表现出最强的电催化效果,氧化峰电流最大。示差脉冲伏安(DPV)测定结果显示,在pH=7的磷酸缓冲液中,BPA的峰电流在1.0×10^-7~6.0×10^-5 mol/L浓度内呈线性变化,检测限可达7.2×10^-8 mol/L,同时Ag@C-3/SPE修饰电极具有超强的抗干扰能力。

Using the hydrothermal method,a series of Ag@C core-shell nanostructures of carbon coated silver nanoparticles were obtained by changing the reaction time.The high-sensitivity electrochemical sensors for determining bisphenol A(BPA)were prepared by modifying screen-printed electrodes with the Ag@C core-shell nanostructures.The scanning electron microscopy(SEM)results show that the Ag@C core-shell nanostructures are uniformly spherical,and each microsphere contains an Ag particle with a diameter of about 80 nm.With the increase of hydrothermal reaction time,the carbon shell thickness and the diameter of the Ag@C microspheres increase.The cyclic voltammetry(CV)test result indicates that the Ag@C nanostructures have significant catalytic effect on the oxidation of BPA.The Ag@C-3 prepared by hydrothermal reaction for 4 h exhibits the largest electrocatalytic activity to BPA and the highest oxidation peak current due to its appropriate carbon shell thickness.The differential pulse voltammetry(DPV)result shows that in the phosphoric acid buffer solution with pH=7,the peak current of BPA shows a linear change in the BPA concentration of 1.0×10^-7-6.0×10^-5 mol/L,the detection limit reaches 7.2×10^-8 mol/L,and the Ag@C-3/SPE modified electrode has significant anti-interference ability.