Advanced MIPs for pesticide detection

Abstract

in 60% of all tested water sites in Flanders imidacloprid, the most used third generation neonicotinoid insecticide, exceeds the predicted no effect concentration. It is harmful to the environment but no efficient purification method exists to date. Molecularly Imprinted Polymers (MIPs), highly sensitive materials with cavities that are complementary to the target, are ideal for these purification purposes. The cavities are formed by hydrogen bonding between the target molecule and functionalities from monomers. However, MIPs today require a lot of crosslinker to ensure MIP stability. This comes at the cost of functionalities, leading to decreased MIP efficiency. To maintain MIP stability while increasing its efficiency, the functional crosslinker N,O-bis(methacryloyl)ethanolamine (NOBE) was used to synthesize MIPs and their efficiency was compared with conventional MIPs through static absorption measurements. The binding efficiency of NOBE MIPs in acetonitrile was better than conventional MIPs, with significant specific binding occuring as opposed to no specific binding in conventional MIPs. In buffered samples, however, no specific binding was observed in either system. To increase the specificity of the system further, threonine-NOBE, a NOBE derivate with an extra acidic functionality, was synthesized from the amino acid L-threonine under the hypothesis that more functionalities lead to increased binding efficiencies. Threonine-NOBE synthesis was succesful, but iosolation has not been performed yet.