Water-compatible molecularly imprinted polymers (MIPs) for caffeine were synthesized in aqueous medium with a new functional monomer, 1-(a-methyl acrylate)-3-methylimidazolium bromide (1-MA-3MI-Br), which had p-p and hydrogen-bonding interactions. Caffeine-imprinted polymers were prepared in suspension polymerization with 1-MA-3MI-Br and methacrylic acid (MAA), which only had hydrogen bonding, as a functional monomer. For the specific binding characteristics of the new functional monomer 1-MA-3MI-Br, the adsorption capacity and relative separation factor (b) of MIPs for caffeine were significantly enhanced. The maximum adsorption capacities of 1-MA-3MI-Br-MIP and MAA-MIP imprinted microspheres for caffeine were 53.80 and 28.90 lmol/g, respectively. Moreover, the relative separation factors were measured by comparison of the separation characteristics under competitive adsorption conditions. The results showed that the b of MAA-MIP for caffeine relative to theophylline was only 1.65; this showed a very poor recognition selectivity for caffeine, but b of 1-MA-3MI-Br-MIP for caffeine with respect to theophylline was remarkably enhanced to 3.19; this showed an excellent recognition selectivity and binding affinity toward caffeine molecules in an aqueous environment.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.