纳米金信号放大分子印迹电化学传感器用于雌二醇的检测

目的构建分子印迹聚合物修饰的具有高灵敏度和选择性的电化学传感器,实现对雌二醇(E2)小分子的快速检测,并为农药残留及环境污染物的检测提供依据。方法以对氨基苯硫酚作为印迹聚合功能单体,通过Au-S共价键连接在用于信号放大的纳米金颗粒表面,并利用氢键与模板分子雌二醇连接形成单层膜,最后将上述电极在含有雌二醇和对氨基苯硫酚的溶液中进行电聚合,形成具有大量印迹位点的聚合物膜。用电化学循环伏安法和电化学阻抗谱对修饰电极进行表征。结果在电极表面自组装制备了含E2印迹位点的聚合物膜,用计时电流法测量溶液中E2在1.0×10-8~1.0×10-12mg/ml范围内呈线性(R2=0.9989),最低检测限为1.51×10-12mg/ml,相同条件下制备的6支电极具有良好的重复性(相对标准偏差为2.44%,n=6)。结论纳米金信号放大的分子印迹电化学传感器可以快速灵敏地对雌二醇进行检测。

MOLECULARLY IMPRINTED ELECTROCHEMICAL SENSOR BASED ON GOLD NANOMATERIALS AMPLIFICATION FOR ESTRADIOL DETECTION

Objective To construct an electrochemical sensor of high sensitivity and selectivity modified with molecularly imprinted polymer （MIP） for the rapid detection of estradiol （E2 ）, and to provide the evidence for further detection of pesticide residue, and environmental pollutant. Methods Gold nanopartieles （AuNPs） were electrodeposited on the surface of electrode and were used to increase the electrode surface area as well as to ampli- fy the sensor signal. Functional monomer p-aminothiophenol （ATP） was then combined with AuNPs through Au-S bonds. Moreover, the E2 template was further assembled onto the ATP monolayer by the formation of hydrogen bonds. Finally the electrode in the solution containing estradiol and aminthiophenol was electropolymerized to form polymer film with a large number of imprinting site. The characterization of the modified electrode was optimized via cyclic vohammetry （CV） and electrochemical impedance spectroscopy （EIS）. Results The polymer film containing E2 imprinted site was formed on the surface of the electrode by self-assembly. Electrochemical measurements were performed via chronoamperometry,and the curve obtained was linear in the range of 1.0×10^-8 to 1.0×10^-12mg/mL with a detection limit of 1.51×10^-12mg/mL （R2 =0. 9989）. Six electrodes prepared in the same conditions indica- ted good sensor-to-sensor reproducibility （ RSD = 2.44% , n = 6）. Conclusion This electrochemical sensor based on electropolymerized molecularly imprinted polymer modification and gold nanomaterials amplification can be used for rapid detection of estradiol.