Chem. J. Chinese Universities ›› 2018, Vol. 39 ›› Issue (11): 2386.doi: 10.7503/cjcu20180283

• Analytical Chemistry • Previous Articles     Next Articles

L-Cystine Sensor Based on Modification of Extended Gate of FET with Polydithiodipropanesulfonic Acid Membrane

YANG Jia, ZHANG Yuyang, LIU Chen, LI Jiaxin, XIAO Zhongliang*(), LI Dan, ZHANG Ling, CAO Zhong*()   

  1. Collaborative Innovation Center of Micro/nano Biosensing and Food Safety Inspection, 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:2018-04-11 Online:2018-11-10 Published:2018-10-16
  • Contact: XIAO Zhongliang,CAO Zhong E-mail:xiaozhongliang@163.com;zhongcao2004@163.com
  • Supported by:
    † Supported by the National Natural Science Foundation of China(Nos.31527803, 21545010).

Abstract:

A novel sensing device capable of detecting L-cystine was constructed by designing the gate gold electrode(GGE) of a field effect transistor(FET) to extend a certain distance and self-assembly of polydithiodipropanesulfonic acid(SPS) on the surface of GGE. The topological structure of the modified GGE was characterized by means of scanning electron microscopy. Through electrochemical cyclic voltammetry and impedance analysis together with X-ray photoelectron spectroscopy, the response mechanism of the SPS modified GGE for the L-cystine detection has been well investigated. With electrostatic interaction, the SPS poly-anion membrane with negative charge in aqueous solution could adsorb the L-cystine molecules containing positive charge, which may form a double electric layer resulting in change of membrane potential on the sensing interface by recognition of monovalent organic ammonium ion. The electrode exhibited a nice linear potential performance to L-cystine in the range of 5.0×10-6~1.0×10-3 mol/L, with a slope of (58.25±1.5) mV/-pc(25 ℃) and a detection limit of 2.69×10-6 mol/L. The response time for L-cystine was very fast(30 s). The electrode also had good reproducibility and stability. Almost no interferences from common amino acids such as L-glycine, L-alanine, L-valine, L-aspartate, L-proline, L-threonine, L-histidine, L-leucine, L-tryptophan or L-methionine can be observed. Moreover, the electrode can be applied to the determination of L-cystine in real pig serum samples with recovery rate of 91.2%—107.8%. It shows that the sensing device is expected to become a kind of simple and accurate means for the L-cystine analysis.

Key words: L-Cystine, Gate gold electrode, Field effect transistor, Polydithiodipropanesulfonic acid, Potentiometric sensor

CLC Number: 

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