Study On Preparation And Application Of Chemically Modified Electrode

Chemically modified electrode (CME) with the characters of high sensitivity, goodselectivity, fast response, etc., develops very rapidly in recent years. Elctroanalysis andelectrocatalysis are two important applications of CME. In this article, different kinds of CMEare prepared and applied to solve two practical problems: chiral electrochemical recognition ofenantiomers and electrocatalysis of oxygen reduction reaction. The performances of both CMEsare good.1. Nitrogen and sulfur dual doped-carbon nanotubes and mesoporous carbon is preparedby pyrolyzing the mixture of bi-nuclear phthalocyanine hexasulfonate and nano-calciumcarbonate. The template is removed by diluted hydrochloric acid. Scanning electronicmicroscopy, transmission electronic microscopy, X-ray photoelectron spectroscopy, nitrogenadsorption-desorption and electrochemical method was applied to characterize the product,which show that nitrogen and sulfur are doped into carbon, and has the morphology of bothnanotubes and mesopores. The product is modified on a glassy carbon electrode and applied inelectrocatalysis of oxygen reduction reaction. The results show that the obtained-modifiedelectrode has good electrocatalytic activity, stability and selectivity.2. Glassy carbon electrode is modified by oxidizing L-cysteine and the modified electrodeis characterized by electrochemical impedance spectrum. The result shows that the oxidationproduct of L-cysteine (L-cysteic acid) is modified on the surface of glassy carbon electrode. Themodified electrode is applied to recognize the conformation of L/D-tyrosine. Different peakpotentials of cyclic voltammogram are observed on different conformations of L/D-tyrosine.The modified electrode is then applied in a racemic solution of L/D-tyrosine. A linearrelationship is observed between oxidation peak potential and L-tyrosine%.