Comparison of monofunctional and multifunctional monomers in phosphate binding molecularly imprinted polymers

Abstract

In this study, molecularly imprinted polymers (MIPs) prepared using a multifunctional and a monofunctional monomer were compared with respect to their affinities, selectivities, and imprinting efficiencies for organophosphates. This is of interest because multifunctional monomers have higher affinities than traditional monofunctional monomers for their target analytes and thus should yield MIPs with higher affinities and selectivities. However, polymers containing multifunctional monomer may also have a higher number of unselective, non-templated binding sites. This increase in background binding sites could lead to a decrease in the magnitude of the imprinting effect and in the selectivity of the MIP. Therefore, phosphate selective imprinted and non-imprinted polymers (NIPs) were prepared using a novel multifunctional triurea monomer. The binding properties of these polymers were compared with polymers prepared using a monofunctional monourea monomer. The binding affinities and selectivities of the monomers, imprinted polymers, and NIPs were characterized by NMR titration, binding uptake studies, and binding isotherms. MIPs prepared with the triurea monomer showed higher binding affinity and selectivity for the diphenylphosphate anion in organic solvents than the MIPs prepared with the monofunctional monomer. Surprisingly, the binding properties of the NIPs revealed that the polymers prepared using the multifunctional and monofunctional monomers were very similar in affinity and selectivity. Thus, the multifunctional monomers increase not only the affinity of the MIP but also enhance the imprinting effect.

Insight into molecular imprinting in precipitation polymerization systems using solution NMR and dynamic light scattering

“…In several previous investigations, template‐functional monomer complexation has been studied using solution NMR (Sellergren et al ., 1988; Lübke et al ., 2000; Ansell and Kuah, 2005; Hall et al ., 2005; Molinelli et al ., 2005; Wei et al ., 2007; Ansell et al ., 2008; Ansell and Wang, 2009). The conditions in these experiments were designed to simulate the pre‐polymerization mixture used for preparing monolithic MIPs, and often excluded the cross‐linking monomer and initiator (Takeuchi et al ., 2000; Wulff and Knorr, 2002; Svenson et al ., 2004; Hall et al ., 2005; Li et al ., 2005; Matsui et al ., 2007; Liu and Wulff, 2008; Wu et al ., 2008). To the best of our knowledge, there have been no studies of pre‐polymerization mixtures in precipitation polymerization systems.…”

Molecularly imprinted nanoparticles prepared by miniemulsion polymerization as selective receptors and new carriers for the sustained release of carbamazepine

“…These nano-droplets containing CBZ (as template), methacrylic acid (MAA, as functional monomer), and ethylene glycol dimethacrylate (EGDMA, as cross-linker) served as nanoreactors. The choice of monomers is critical to improve imprinting efficiency and other properties of polymers [25]. MAA and EGDMA as monomer found to be biocompatible and non-toxic.…”

Templated polymers enable selective capture and release of lysophosphatidic acid in human plasma via optimization of non-covalent binding to functional monomers

“…29 2-Propenoic acid, 2-methyl-18-methyl-8-[2-[[[[2-[(2-methyl-1-oxo-2-propen-1-yl)oxy]ethyl]amino]carbonyl] amino] ethyl]-4,12,17-trioxo-16-oxa-3,5,8,11,13-pentaazanonadec-18-en-1-yl ester. Tris(2-aminoethyl) amine (2.2 g, 15.04 mmol) is dissolved in 110 mL CH 2 Cl 2 and cooled to 0 °C before 2-isocyanatoethyl methacrylate (7.0 g, 45.12 mmol) is added dropwise.…”