Chemiluminescence sensor for sulfonylurea herbicide using molecular imprinted microspheres as recognition element

Uniform molecular imprinting microspheres were prepared using precipitation polymerization with thifensulfuron-methyl (TFM) as template, acrylamide as functional monomer and ethylene glycol dimethacrylate as cross-linker. TFM could be selectively adsorbed on the molecularly imprinted polymers (MIPs) matrix through the hydrogen bonding interaction and the adsorbed TFM could be sensed by its strikingly enhancing effect on the weak chemiluminescence (CL) reaction between luminol and hydrogen peroxide. On this basis, a novel CL sensor for the determination of TFM using MIPs as recognition elements was established. The logarithm of net CL intensity (ΔI) is linearly proportional to the logarithm of TFM concentration (C) in the range from 1.0 × 10−9 to 5.0 × 10−5 mol L−1 with a detection limit of 8.3 × 10−10 mol L−1 (3σ). The results demonstrated that the MIP–CL sensor was reversible and reusable and that it could strikingly improve the selectivity and sensitivity of CL analysis. Furthermore, it is suggested that the CL enhancement of luminol–H2O2 by TFM might be ascribed to the enhancement effect of CO2, which came from TFM hydrolysis in basic medium. Copyright © 2010 John Wiley & Sons, Ltd.