Abstract
A chemically modified electrode was successfully prepared by self-assembling bi-(2-aminoethyl)-aminodithiocarboxyl acid (BADTC) on a gold electrode and its further derivatization to form a monolayer of nickel hexacyanoferrate (NiHCF). Its electrochemical characteristics were investigated by cyclic voltammetry and an AC impedance spectroscopy technique. The electrochemical behavior of this modified electrode greatly depended on the kinds and concentrations of cations. Among the studied cations, including Li+ , K+ , Na+ , NH4+ , Ca2+ and Mg2+ etc., K+ was found to be the most appropriate ion to participate in the electrochemical process of this BADTC-NiHCF film modified electrode, as a counterion. The heterogeneous rate constants of this film modified electrode were 0.95, 4.97 s-1 in 0.001 and 0.01 mol L-1 KCl solutions, respectively, obtained from the AC impedance. Moreover, this monolayer film modified electrode showed a good molecular-recognition ability for K+ and NH4+.
