Chemical Modified Electrode And Its Application Study In The Environmental Analysis

Amino acid is the most essential matter in biological body, which has some specialcharacters for having amino group and carboxyl. Amino acid can be modified on the electrodeby chemical way or electrochemical way. The modified electrodes are applied for thedetermination of metal ion, biological molecule, organic pollutant and so on, which showssome special advantages.Chemically modified electrode is currently an active area of research. It can be designedaccording to our demand, and have shown splendid prospects in sensitivity and selectivity.In this paper, the polymerization condition of p-toluene sulfonic acid at glassy carbonelectrode and the electrochemical characeristics of the modified electrode had beeninvestigated. It was found that the the polymer showed strong electrocatalytic effects onoxidation of Dopamine (DA) and Ascorbic acid (AA). In differential pulse votammetric(DPV) measurements, the poly(p-toluene sulfonic acid) film modified electrode can separatethe DA and AA oxidation potentials by about 192mV and can be used to the simultaneousdetermination of DA and AA. The electrode shows excellent sensitivity, good selectivity andantifouling properties.In the paper, Glassy carbon electrode (GCE) was modified with electropolymerized filmsof poly (aspartic acid) (p-Asp), poly (glutamic acid) (p-Glu) and poly (phenylalanine) (p-Phe),respectively. These three kinds of polymer-modified electrodes (PMEs) were used tosimultaneous electrochemical determination of hydroquinone (HQ) and catechol (CC) andshow an excellent electrocatalytical effect on the oxidation of HQ and CC. A successfulelimination of the fouling effect by the oxidized product of HQ on the response of CC hasbeen achieved at these polymer-modified electrodes. The proposed three kinds ofpolymer-modified electrodes had been applied to simultaneous determination of HQ and CCin a water sample with simplicity and high selectivity.Also, we had studied that the structure of the amino acid affected on the oxidation of HQand CC. The result showed that the structure of the amino acid had no obvious effects on theelectrocatalysis of HQ and CC.