A new stable -immobilized poly(butyl viologen)-modified electrode for dopamine determination

A new kind of highly stable Fe ( CN ) 6 3 − / 4 − /poly(butyl viologen) (PBV) thin film, without any sealing layer, as a modified electrode for dopamine oxidation was proposed. In this work, Fe ( CN ) 6 4 − were entrapped within the PBV film to form a charge transfer complex. The electrochemical and electrocatalytic properties were studied using cyclic voltammetry (CV) and amperometric techniques, in conjunction with a rotating-disk electrode. The results show a highly stable and symmetric redox behavior for the Fe ( CN ) 6 3 − / 4 − couple with peak–peak separation of 3 mV at a scan rate of 5 mV/s. The electron transfer rate constant for the Fe ( CN ) 6 3 − / 4 − couple within the film, the catalytic rate constant between dopamine and Fe ( CN ) 6 3 − / 4 − , and the Michaelis–Menton constants are investigated. Moreover, the result shows an excellent mediation for dopamine oxidation.