Electrochemical behavior of dopamine in the presence of phosphonate and the determination of dopamine at phosphonate modified zirconia films electrode with highly antifouling capability

Electrochemical oxidation of dopamine (DA) generally leads to electrode passivation due to accumulation of reaction products. Addition of ethylenediamine-tetramethylene phosphonic acid (EDTMP) to the supporting electrolyte can decrease the formal potential (E-0') of DA oxidation and enhance the antifouling capability of bare Au electrode due to the strong interaction between EDTMP and DA. Subsequently, an EDTMP modified zirconia films electrode is synthesized by using self-assembly method. The electrochemical measurements reveal the modified electrode possesses the excellent antifouling capability for DA oxidation and long-termed stability. In addition, the EDTMP modified zirconia films electrode can be used as a functional interface to sensitively and selectively detect DA in the presence of highly concentrated ascorbic acid (AA) due to the electrostatic interactions between the negatively charged phosphonic acid groups with DA. (C) 2010 Elsevier Ltd. All rights reserved.