表面胶团修饰电极电化学测定双酚A的增敏机理及抗污性能研究

分别以2种阴离子表面活性剂(SDS、SDBS)、3种季铵盐阳离子表面活性剂(CTAB、TTAB、DTAB)和2种季铵盐型双子表面活性剂(12-3-12、12-4-12)修饰碳糊电极。通过原子力显微镜、接触角以及分析物在电极表面的电化学行为探讨了不同表面活性剂在电极表面的吸附情况,推测在浓度大于临界胶束浓度(CMC)时,季铵盐型阳离子表面活性剂CTAB、TTAB、12-3-12和12-4-12在碳糊电极表面形成了圆柱形的表面胶团,而DTAB和SDS可能是饱和单分子层吸附。以BPA为分析物,研究了表面活性剂修饰电极对BPA的电化学增敏机理,结果表明修饰电极对双酚A(BPA)的电化学增敏作用主要是因为表面胶团对BPA的增溶作用,表面活性剂和BPA间的阳离子-π作用是表面胶团增溶BPA的主要原因。

Investigation on Sensitization Mechanism and Pollution Resistance of Electrochemical Detection of Bisphenol A Using Admiclles Modified Electrode

Two anionic surfactants(SDS and SDBS),three quaternary ammonium cationic surfactants (CTAB,TTAB and DTAB) and two quaternary ammonium gemini surfactants(12-3-12 and 12-4-12) were used to modified the CPE.Different kinds of surfactants adsorbed on the CPE were studied by using atomic force microscopy,contact angle and the electrochemical behavior of BPA.The results suggested that as the concentration was greater than the CMC,the quaternary ammonium cationic surfactants(e.g.CTAB,TTAB,12-3-12 and 12-4-12) formed the cylindrical admicelles on the surface of CPE,while DTAB and SDS may be the saturated monolayer adsorption.The electrochemical catalytic mechanism of the admicelle for BPA was investigated,and the results showed that the electrochemical sensitization effect to BPA was mainly due to the admicelle solubilization to the BPA.Furthermore,cation-π effect between cationic surfactants and BPA was the key for BPA solubilization.Therefore,CTAB admicelle modified CPE could be used to detect BPA sensitively.