Use of interelectrode material transfer of nickel and copper‑nickel alloy to carbon fibers to assemble miniature glucose sensors

Abstract Electrochemical deposition of the material released by anodizing nickel and copper nickel alloy in pure water onto carbon fiber microelectrodes was used to assemble miniature glucose sensors. The composition and morphology of the deposits was investigated by scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. The deposition of anode-derived materials proceeded by two consecutive mechanisms, which are explained in detail. The electrochemical properties of the designed electrodes were subsequently investigated by cyclic voltammetry and electrochemical impedance spectroscopy. The different Ni- and mixed CuNi-modified microelectrodes were examined as glucose sensors and the best performing electrodes based on the alloyed deposit exhibited very high sensitivity (5720 μA mM −1  cm −2 ), low detection limit (0.3 μM) and ability to quantify glucose in blood serum.