PNNL

Abstract

Au-ZrO2-SiO2 nanocomposite spheres were synthesized and used as selective sorbents for the solid-phase extraction (SPE) of orananophosphorous agents. A non-enzymatic electrochemical sensor based on an Au-ZrO2-SiO2 modified electrode was developed for selective detection of orananophosphorous pesticides (OPs). The Au-ZrO2-SiO2 nanocomposite spheres were synthesized by hydrolysis and condensation of zirconia n-butoxide (TBOZ) on the surface of SiO2 spheres and then introduction of gold nanoparticles on the surface. Transmission electron microscope and X-ray photoelectron spectroscopy were performed to characterize the formation of the nanocomposite sphere. Fast extraction of OP was achieved by Au-ZrO2-SiO2 modified electrode within 5 min via the specific affinity between zirconia and phosphoric group. The assay yields a broad concentration range of paraoxon-ethyl from 1.0 to 500 ng/mL with a detection limit 0.5 ng/mL. This selective and sensitive method holds great promise for the enrichment and detection of OPs.