Pd/Ni/Si-microchannel-plate-based amperometric sensor for ethanol detection

► The first study to apply silicon microchannel plate (MCP) in amperometric ethanol sensors. ► The Pd/Ni/Si MCP electrode exhibits many desirable characteristics such as high sensitivity, good stability, acceptable reproducibility, and quick response. ► The excellent performance arises from the highly dispersed palladium nanoparticles and the three-dimensional structure of the silicon MCP. ► The use of the Si MCP array as the backbone is compatible with conventional microelectronics processing. A sensitive amperometric ethanol sensor composed of highly dispersed palladium nanoparticles on a vertically aligned nickel-coated silicon microchannel plate (MCP) has been constructed. The morphology of the palladium-modified nickel-coated silicon MCP electrode was characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The performance of the Pd/Ni/Si MCP electrode for the electrochemical detection of ethanol was investigated by cyclic voltammetry and amperometry. The electrode with three-dimensional structure shows high-catalytic activity towards the oxidation of ethanol in a 0.10 M KOH solution. At an applied potential of −0.10 V, the Pd/Ni/Si MCP electrode presents a high sensitivity of 0.992 mA mM −1 cm −2, and the detection limit is 16.8 μM. The linear range is up to 60 mM with a linear correlation coefficient of 0.998. The Pd/Ni/Si MCP electrode also possesses excellent electrocatalytic properties, rapid response, and good stability and repeatability. This novel electrode has great potential in the accurate and effective detection of ethanol.