A micro-solid phase extraction device to prepare a molecularly imprinted porous monolith in a facile mode for fast protein separation

A molecularly imprinted polymeric monolith was synthesized in an aqueous environment in 15 min via UV-irradiation. The imprinted monolith was composed of hydroxyethyl methacrylate as monomer, dimethyl amino ethyl methacrylate as functional monomer, methylene bisacrylamide and piperazine di- acrylamide as crosslinkers and human serum albumin as template molecule. The synthesis took place in a PDMS-based device (2.5 cm long) yielding a micro-solid phase extraction column (3 ×5 mm) with two built-in fingertight connectors for an infusion pump and fraction collector. The imprinted monolith displayed the characteristic features of a porous polymeric monolith, had dimethyl amino ethyl methacry- late and human serum albumin as functional groups within the monolith and showed high permeability (0.51 ×10 −13 m 2 ). 85% of the imprinted cavities were readily available for rebinding of human serum albumin with an imprinting factor of 1.3. In comparison to a non-imprinted monolith, molecular imprint- ing increased human serum albumin adsorption by > 30%. Imprinted monolith displayed selectivity for human serum albumin over other competing proteins (human transferrin, ovalbumin and carbonic an- hydrase) with similar or different isoelectric points and size. Human serum albumin was adsorbed (in dynamic mode) with > 98% selectivity from diluted human plasma using the imprinted monolith de- vice. Device to device reproducibility and reusability of the device for 5 cycles showcase the imprinted monolith micro-device efficiency.