富镉离子CdS量子点电化学发光法检测L-半脐氨酸

采用一锅法,通过控制镉硫比合成了表面富镉离子的硫化镉量子点,利用L-半胱氨酸可与量子点表面Cd2+结合,使量子点表面钝化,从而增强其电化学发光信号的性质,实现了对L-半胱氨酸的选择性检测.对合成的量子点进行了表征,优化了检测条件.在优化的条件下,L-半胱氨酸在5.0×10-9~1.0×10-5 mol/L浓度范围内与ECL信号呈良好的线性关系,检出限为1.2×10-9 mol/L(S/N=3).本方法对L-半胱氨酸具有良好的选择性,用于实际样品中L-半胱氨酸的测定,结果令人满意.

Ultrasensitive Determination of L-Cysteine Based on Its Enhancement to Electrochemiluminescence of CdS Quantum Dots with Cd2+Rich Surface

A novel electrochemiluminescence ( ECL) method for the determination of L-cysteine ( L-Cys) was established. water-soluble CdS quantum dots ( QDs) with Cd2+rich surface were synthesized via a controllable one-poe approach. The mercapto group in L-cysteine molecule can specifically interact with excessive Cd2+on the surface of CdS QDs, resulting in enhancement of ECL intensity of the CdS QDs, which can be used for the detection of L-Cys. Under the optimal experimental conditions, the enhancement of ECL intensity was linear with the concentration of L-Cys in the range of 5. 0×10-9-1. 0×10-5 mol/L. The limit detection of (S/N=3) was 1. 2×10-9 mol/L. In comparison with other methods for detecting L-Cys, this method is more simple and selective, and can be applied to detect L-Cys in real sample with satisfactory results.