Poly(3,4-ethylenedioxythiophene)-modified Ni/silicon microchannel plate electrode for the simultaneous determination of ascorbic acid, dopamine and uric acid

A Ni/silicon microchannel plate (Ni/Si MCP) electrode modified with poly(3,4-ethylenedioxythiophene) (PEDOT) was successfully fabricated. The analytical performance of prepared electrode for the simultaneous determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA) was investigated by using cyclic voltammetry and differential pulse voltammetry (DPV). The sensitivities for AA, DA and UA obtained by DPV are 5.39 A m(-2) mM(-1), 0.054 A m(-2) mu M-1 and 0.022 A m(-2) mu M-1, respectively. The calculated detection limits were 10 mu M (AA), 1.5 mu M (DA) and 2.7 mu M (UA). The prepared electrode was successfully applied to the detection of AA, DA and UA in urine samples. The experiments illustrate that Ni/Si MCP is a good electrode material which provides a large surface-to-volume ratio and enhances the selectivity and sensitivity.