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 (Au-nps) embedded in (3-aminopropyl)triethoxysilane (APS) derived silicate sol-gel three-dimensional network (APS-Au-nps). The APS-Au-nps 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-Au-nps 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-Au-nps modified glassy carbon electrode (GC/APS-Au-nps,) with a large decrease in the over potentials to the extent of similar to 750 mV, similar to 600 mV and similar to 250 mV, respectively. The electrochemical sensors designed using the APS-Au-nps modified electrode was also used for the concurrent detection of N2H4, SO32- and NO2- in a mixture. The electrochemical sensor prepared using APS-Au-nps modified electrode was very stable and highly sensitive, and showed fast response. (c) 2007 Published by Elsevier B.V.