Organophosphorus pesticides and warfare agents are not readily hydrolyzed in aqueous media without applying extremes of pH, heat, or bleach. We show that suspensions of magnetite (Fe3O4) nanoparticles modified with a common antidote, 2-pralidoxime (PAM), its polymeric analog, poly(4-vinylpyridine-N-phenacyloxime-co-acrylic acid), or poly(N-vinylimidazole-co-acrolein oxime-co-acrylic acid) (PImAA) catalyze the hydrolysis of organophosphate (OP) compounds such as diisopropyl fluorophosphate (DFP) or insecticide diethyl-p-nitrophenyl phosphate (paraoxon) serving as models of the warfare nerve agents, at neutral pH. The oxime-modified magnetite particle serves as a nano-sized particulate carrier with a powerful a-nucleophile, the oximate group, immobilized on its surface. The rates of OP hydrolysis by the PAM- or PImAA-modified magnetite are comparable to those of the most potent copper-based catalysts. The oxime-modified magnetite nanoparticles are colloidally stable at neutral pH and are readily recovered for reuse from the aqueous milieu by high-gradient magnetic separation methods with no loss of catalytic activity.
Journal: TechConnect Briefs
Volume: 1, Technical Proceedings of the 2006 NSTI Nanotechnology Conference and Trade Show, Volume 1
Published: May 7, 2006
Pages: 377 - 380
Industry sector: Advanced Materials & Manufacturing
Topics: Nanoparticle Synthesis & Applications