Specific binding of cholic acid by cross-linked polymers prepared by the hybrid imprinting method

A cholic acid-imprinted polymer has been prepared by a hybrid imprinting method involving the use of a template-containing monomer, 3α-methacryloyl cholic acid methyl ester. The removal of the template can afford the polymer with cavities and carboxylic acid groups well positioned in these cavities for the specific binding of cholic acid via hydrogen bonding. The maximum binding capabilities for the imprinted and non-imprinted polymers were determined to be 344.8 and 43.6 μmol/g, respectively. Scatchard analysis indicates the existence of two kinds of binding sites on the imprinted polymer. The imprinted polymers exhibit high affinity and good recognition selectivity for cholic acid in comparison to other compounds with similar molecular structures. The size-specific binding and hydrogen bonding may be both important for the binding of cholic acid by the imprinted polymers.