Soluble and Processable Phosphonate Sensing Star Molecularly Imprinted Polymers

Abstract

Soluble molecularly imprinted polymers (MIPs) were prepared by reversible addition fragmentation chain transfer (RAFT) polymerization followed by ring-closing metathesis (RCM). The polymerization was done in the presence of a template to generate a processable star MIP. The core of the star polymer was a dithiobenzoate-substituted tris(β-diketonate)europium(III) complex. The tris(β-diketonate)europium(III) complex served as a polymerization substrate for the three-armed RAFT-mediated star polymer and as a luminescent binding site for dicrotophos, an organophosphonate pesticide. The star arms were AB block copolymers. Block A was either 1-but-3-enyl-4-vinylbenzene or a mixture of 1-but-3-enyl-4-vinylbenzene and styrene. Block B was styrene or methyl methacrylate. The but-3-enyls of block A were reacted by RCM with a second generation Grubbs catalyst to give an intramolecularly cross-linked core. The intramolecularly cross-linked MIP was soluble in common organic solvents. The 30% cross-linked soluble and processable star MIP was applied to the determination of dicrotophos with sub-ppb level detection limits.