利用恒电压沉积纳米银制备了对吡虫啉响应良好的电化学传感器。采用扫描电镜(SEM)、电化学阻抗谱(EIS)对电极进行了表征。探讨了缓冲液pH、扫描速率、干扰物质对实验结果的影响。研究表明,最佳实验条件(0.01 mol/L、pH=7的PBS缓冲液,扫描速率100 mV/s)下,在10~100 μmol/L浓度范围内含吡虫啉线性伏安扫描的还原峰电流与其浓度呈线性关系(R²=0.980 0),LOD值为0.04 μmol/L。该修饰电极具有电稳定性良好、可重复使用等一系列优点。对河水的添加回收率为90.05%~103.1%,与液相色谱测定的结果相符,表明该传感器在实际样品检测和环境保护中具有良好的应用前景。

A novel electrochemical sensor for determining imidacloprid is constructed by constant voltage deposition of nano-silver modified electrode,and characterized by means of scanning electron microscopy and electrochemical impedance.The influences of buffer pH,scanning rate,and interfering substances on the experimental results are investigated.It is demonstrated that under the optimal experimental conditions (a PBS buffer with a concentration of 0.01 mol·L^-1 and a pH of 7,and a scanning rate of 100 mV·s^-1),the reduction peak current of imidacloprid responds linearly to its concentration in the range of 10-100 μmol·L^-1 with a R² of 0.980 0 and a LOD of 0.04 μmol·L^-1.The modified electrode exhibits a series of advantages such as good electrical stability and reusability.It shows the recoveries of 90.05%-103.1% to imidacloprid in river water,which are consistent with the results from liquid chromatography,indicating the potential application in real samples and environmental protection.

张宗元(2000-),男,硕士生;赵佳(1980-),女,博士,讲师,研究方向为环境污染物的检测与分析,通讯联系人,82215004@qq.com。