Fabrication of nanoporous gold thin films on glass substrates for amperometric sensing of aniline

Nanoporous gold (NP-Au) thin films were fabricated on glass substrates by dealloying an Au-Si alloy produced by co-deposition of Au and Si. Si was selectively removed from the Au-Si alloy with potassium hydroxide solution, which is a very simple and safe dealloying method. We investigated the optimum conditions for sputtering and dealloying to obtain stable and durable nanoporous films. The NP-Au films were used as a working electrode for amperometric sensing of aniline in water and exhibited a wider sensing range and lower detection limit than NP-Au electrodes fabricated on Si substrates with HF etchant. The larger surface roughness factor of the NP-Au sensor is responsible for the enhanced sensing performance.