Chem. J. Chinese Universities ›› 2020, Vol. 41 ›› Issue (2): 268.doi: 10.7503/cjcu20190448

• Analy Chemistry • Previous Articles     Next Articles

Rapid and Sensitive Detection of L-Cysteine Based on Mono(6-mercapto-6-deoxy)-β-cyclodextrin Modified Gold Electrode

PENG Yuyu,WANG Yu,YU Xinyao,ZENG Julan,XIAO Zhongliang,CAO Zhong()   

  1. Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation, School of Chemistry and Biological Engineering, Changsha University of Science and Technology, Changsha 410114, China
  • Received:2019-08-09 Online:2020-02-10 Published:2019-11-14
  • Contact: Zhong CAO E-mail:zhongcao2004@163.com
  • Supported by:
    ? Supported by the National Natural Science Foundation of China(31527803);Supported by the National Natural Science Foundation of China(21545010);the Natural Science Foundation of Hunan Province, China(2017JJ1026)

Abstract:

A simple, rapid and sensitive L-cysteine(L-Cys)potentiometric electrochemical sensor was constructed by using mono(6-mercapto-6-deoxy)-β-cyclodextrin(HS-β-CD) self-assembled on surface of gold electrode(GE) via gold-sulfur bond. The electrochemical behavior of the electrode membrane surface was investigated through cyclic voltammetry and impedance analysis. Scanning electron microscopy and X-ray photoelectron spectroscopy have also demonstrated the film assembly effectiveness of the electrode. And the interaction mechanism of the electrode was that the cyclodextrin cavity of HS-β-CD immobilized on the gold surface can adsorb and bind electronegative L-Cys through intermolecular force, resulting in change of the membrane potential on the electrode surface and further realization of supramolecular selective recognition of L-Cys. In the optimal condition, the modified electrode had good potential response feature to L-Cys in PBS(pH=6.0) with a linear range of 1.0×10 -7—1.0×10 -4 mol/L and a slope of (-65.29±1.0) mV/pc(25 ℃). The detection limit can reach 6.0×10 -8 mol/L. The electrode responded quickly, which had high stability, good reproducibility, and strong anti-interference ability. The electrode can be well used for the determination of L-Cys in actual pig serum and pig urine samples with recovery rate of 95.0%—104.7%, showing its important application prospects in life science fields.

Key words: L-Cysteine, Mono(6-mercapto-6-deoxy)-β-cyclodextrin, Self-assembled monolayer, Supramole-cular recognition, Potential sensor

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