Acta Phys. -Chim. Sin. ›› 2004, Vol. 20 ›› Issue (02): 207-210.doi: 10.3866/PKU.WHXB20040221

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Electrochemical Properties of L-cysteine Self-assembled Membrane Modified Gold Electrode

Fu Chong-Gang;Su Chang-Hua;Shan Rui-Feng   

  1. School of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059
  • Received:2003-07-25 Revised:2003-09-18 Published:2004-02-15
  • Contact: Fu Chong-Gang

Abstract: Electrochemical quartz crystal microbalance and cyclic voltammetry were employed for studying the formation mechanism and electrochemical properties of the self-assembled membrane formed on the surface of the gold electrode. Experimental results show that specific interaction exists between L-cysteine and the gold electrode surface, additionally, the L-cysteine molecular pairs were formed due to the existence of electrostatic attraction and hydrogen bond between themselves in the solution with the pH around isoelectric point. Consequently, an L-cysteine self-assembled bilayer could be formed on the gold electrode surface. A pair of stable redox peaks were observed with the self-assembled bilayer modified gold electrode when potential scanning in 0.2 mol•L-1 Hac-NaAc buffer solution in the range of -0.2~0.5 V (vs SCE). It was also found that the modified electrode has an obvious electrocatalytic effect on the electrooxidation of ascorbic acid.

Key words: L-cysteine, Self-assembled bilayer, Electrochemical quartz crystal microbalance, Cyclic voltammetry, Electrochemical characteristics