基于L-半胱氨酸/CdTe量子点修饰电极的电化学传感器的制备及其对Pb^(2+)的检测  

Preparation of an Electrochemical Sensor Based on L-cysteine/CdTe Quantum Dots Modified Electrode and Its Detection of Lead Ions

作　　者：许世超[1,2,3] 张忆一 董凯[1] 温俊男 

机构地区：[1]天津工业大学环境与化学工程学院,天津300387 [2]天津工业大学中空纤维膜材料与膜过程省部共建国家重点实验室,天津300387 [3]天津工业大学水质安全评价与保障技术工程中心,天津300387

出　　处：《分析测试学报》2017年第4期524-528,共5页Journal of Instrumental Analysis

基　　金：天津市自然科学基金(11JCZDJC22300;13JCQNJC02600);天津市外国专家局引智项目(Y2012061)

摘　　要：成功制备了由L-半胱氨酸和CdTe量子点作为修饰材料的电化学传感器并用于水体中Pb^(2+)的检测。巯基丙酸修饰的CdTe量子点通过水相合成,表面含有大量羧基,与L-半胱氨酸表面的氨基形成酰胺键,修饰于金电极表面。通过荧光分光光度计、透射电子显微镜、红外光谱、X射线衍射对L-Cys/CdTe QDs复合材料进行表征。采用循环伏安法(CV)研究了L-Cys/CdTe QDs修饰成分在金电极上的电化学性能及CdTe量子点的最佳自组装时间。采用差分脉冲溶出伏安法(DPSV)研究了铅离子在修饰电极上的电化学行为。在优化实验条件下,Pb^(2+)浓度在1.0×10^(-6)~1.0×10^(-2) mol/L范围内与其峰电流呈良好的线性关系,相关系数(r2)为0.993 8,检出限(3σ,n=5)为4.0×10^(-7) mol/L。该传感器具有良好的重现性和稳定性,有望用于实际水样中铅离子的检测。A simple and sensitive electrochemical sensor was fabricated for the detection of Pb2＋ based on L-cysteine（L-Cys）/CdTe quantum dots（QDs） hybrid nanocomposites modified gold electrode（GE）.CdTe QDs were synthesized in aqueous phase.Then,carboxyl labeled CdTe QDs were covalently bonded to L-cysteine on gold electrode,depending on connection between-COOH on MPA-CdTe surface and —NH2 in L-cysteine.The morphology and composition of CdTe QDs and hybrid nanocomposites were characterized by fourier transform infrared spectroscopy（FTIR）,X-ray powder diffraction（XRD）,transmission electron microscopy（TEM）,UV-Vis and fluorescence spectrometry.The electrochemical performance of L-Cys/CdTe nanocomposite and the optimized self-assembly time of CdTe QDs on electrode were investigated by cyclic voltammetry（CV）.The electrochemical behavior of lead ions at L-Cys/CdTe nanocomposite modified gold electrode was investigated by different pulse stripping voltammetry（DPSV）.Under the optimal hybridization conditions,different pulse stripping voltammetric responses of L-Cys/CdTe/GE sensor were in linearity with Pb^2＋ in the concentration range of 1.0×10^-6-1.0×10^-2 mol/L with a detection limit of（3σ,n=5） 4.0×10^-7 mol/L and a correlation coefficient（r2） of 0.993 8.Therefore,the electrochemical sensor modified with L-Cys/CdTe/GE nanocomposites exhibited the advantages of high sensitivity,good reproducibility and stability,providing a potential platform for the fabrication of other electrochemical sensors.

关 键 词：CDTE量子点 L-半胱氨酸 修饰电极 电化学传感器 铅离子 

分 类 号：O657.1[理学—分析化学] O614.433[理学—化学]