A facile electrochemical sensor designed from gold nanoparticles embedded in three-dimensional sol–gel network for concurrent detection of toxic chemicals

An electrochemical sensor was prepared using gold nanoparticles (Aunps) embedded in (3-aminopropyl)triethoxysilane (APS) derived silicate sol–gel three-dimensional network (APS–Aunps). The APS–Aunps modified electrode was found to efficiently electrocatalyze the oxidations of N2H4, SO32- and NO2- in the absence of any other electron transfer mediators/enzyme immobilized in the APS–Aunps modified electrode. The electrooxidation peaks appeared at 0.05, 0.2 and 0.55 V for N2H4, SO32- and NO2- in pH 7.2 at the APS–Aunps modified glassy carbon electrode (GC/APS–Aunps) with a large decrease in the over potentials to the extent of ∼750 mV, ∼600 mV and ∼250 mV, respectively. The electrochemical sensors designed using the APS–Aunps modified electrode was also used for the concurrent detection of N2H4, SO32- and NO2- in a mixture. The electrochemical sensor prepared using APS–Aunps modified electrode was very stable and highly sensitive, and showed fast response.