Preparation of bovine serum albumin imprinting sensitive hydrogels using ionic liquid as co-monomer and stabilizer

Through consulting the Hofmeister series, a novel biocompatible and polymerizable ionic liquid (IL) was designed and used as stabilizer and co-monomer to prepare bovine serum albumin (BSA) imprinted hydrogels. N-isopropylacrylamide (NIPA) was chosen as the assistant monomer for imparting environmental sensitivity to the hydrogels. The stabilizing effect of the IL was verified by circular dichroism. Several parameters, such as the mass ratio of the template protein, IL and crosslinker, the drying method of hydrogels and the elution method of MIHs that could affect the performance of molecular imprinted hydrogels (MIHs) were investigated. The optimum mass ratio of BSA, IL and crosslinker was found to be 200:30:6. The best drying and preferred elution method for the MIHs was achieved by slowly evaporating and washing with 0.5 M NaCl solution at 15 °C, respectively. The MIHs prepared under optimized conditions were subsequently used in the adsorption isotherm, adsorption dynamics, adsorption selectivity, and competition test. The adsorption isotherm revealed that the MIHs showed the best imprinted effect at a BSA concentration of 0.2 mg mL−1 and their imprinting factor at 2.66. The adsorption dynamic studies revealed that the adsorptive rate of the MIHs was much faster than the non-imprinted hydrogels (NIHs), and both of them could be equilibrated in 1 h. The adsorption selectivity and competition tests were conducted to estimate the specific recognition property of the MIHs for BSA. The MIHs showed excellent selectivity and recognition ability to BSA. The strategy of applying biocompatible and polymerizable ILs to imprinting technology may provide a new approach for effective biomacromolecular imprinting.