Electrodeposition of AuNi Alloy Nanoparticles on Mercapto Ionic Liquid–Graphite Composite Film and the Amperometric Determination of Hydroquinone

Mercapto-imidazolium ionic liquid (IL, i.e. 1-methyl-3(2’-mercaptoacetoxyethyl) imidazolium hexafluophosphate)–graphite composite film is prepared. AuNi nanoparticles are electrodeposited on it from aqueous electrolyte. The resulting composite film coated glassy carbon electrode (AuNi–IL–graphite/GCE) is characterized by scanning electron microscopy, energy dispersive X–ray spectroscopy, X–ray diffraction and electrochemical impedance spectroscopy. The electrochemical redox of hydroquinone on the composite film is investigated. The results show that the AuNi–IL–graphite has high catalysis and stability. In neutral solutions, it can yield sensitive and stable amperometric response to hydroquinone. At 0.05 V (vs. SCE) the response current is linear to hydroquinone concentration in the range of 0.5–40 ?M, with a detection limit of 0.05 ?M (S/N=3) and sensitivity of 0.92 ?mA cm-2 ?M-1.