Electrochemical behavior of the self-assembled membrane formed by calmodulin (CaM) on a Au substrate

A membrane of calmodulin (CaM) was successfully fabricated by the self-asse mbly. technique on a Au substrate. The electrochemical response of the memb rane was investigated systematically with cyclic voltammetry (CV) and elect rochemical impedance spectroscopy (EIS) methods, where a redox couple of Fe (CN)(6)(3 -/4-) was employed as the probe. The results showed that a combin ation of CaM with Ca2+ could lead to a decrease of the reaction resistance (R-ct) The most interesting point is that the plots, which were recorded us ing the above two methods for the Au electrode modified with the CaM membra ne (CaM/Au), showed a regular dependence on the pH of the electrolyte studi ed. After serial experiments, we concluded that the results we obtained cou ld be attributed partly to the conversion process of the spatial structure of the CaM. (C) 2001 Elsevier Science B.V. All rights reserved.