Effects of charge density on the recognition properties of molecularly imprinted polyampholyte hydrogels

Molecularly imprinted polymers are synthetic materials designed to selectively bind to a templated molecule. In this study, the effect of including both positive and negative charges simultaneously into the hydrogel network on the selective recognition properties of the MIP is examined. Using 3-methacrylamidopropyl trimethylammonium chloride (MAPTAC) as a cationic monomer and 2-acrylamido-2-methylpropane sulfonic acid (AMPS) as an anionic monomer, various ratios of positive to negative charges were tested. Selective recognition properties were dependant on the type of charged monomer that made up a majority of the hydrogel's mass. Additionally, polyampholyte MIPs exhibited less swelling than previously studied polyelectrolyte hydrogels.