Characterization of iron hexachloroplatinate films and their electrocatalytic properties with NAD+, hemoglobin and O2

Iron hexachloroplatinate (FePtCl6) films have been prepared by mixing Fe2+ and PtCl62- ions in an aqueous KBr solution. The electrochemical quartz crystal microbalance (EQCM), rotating ring-disk electrode, UV-visible absorption spectroscopy, stopped-flow kinetic method and cyclic voltammetry were used to study the deposition and growth mechanism of the iron hexachloroplatinate films. The electrochemical and EQCM properties of the films indicated that a single redox process was confined to the immobilized iron hexachloroplatinate films. The deposition of an iron hexabromoplatinate film occurred when PtIVCl62- was electrochemically reduced to PtIICl64- and Fe3+ to Fe2+. In the aqueous KCl, pH 3.0, solution, PtIVCl62- was electrochemically reduced to PtIICl64- and the Fe2+ reacted with the PtIICl64- and PtIVCl62- species. The electrocatalytic reduction properties of NAD+ and hemoglobin were determined using the iron hexachloroplatinate films. The electrocatalytic and electrochemical reactions of NAD+ with an iron hexabromoplatinate film were investigated using the rotating ring-disk electrode method. The catalytic current increased with the increase of analyte concentration with slope of 1.6 μA/mM.