Investigation of protein imprinting in hydrogel-based molecularly imprinted polymers (HydroMIPs)

We have developed a strategy to produce molecularly imprinted polymers based on polyacrylamide hydrogels for the selective imprinting of bovine haemoglobin (BHb). For the first time, we have explored in detail a variety of template removal strategies including varying ratios of sodium dodecylsulphate:acetic acid (SDS:AcOH) and also the use of a trypsin digest. The optimum ratio of SDS:AcOH was found to be a 10% (w/v):10% (v/v) for the most effective template removal. This resulted in >90% (imprinting efficiency) of re-loaded template (protein) molecule being selectively bound within the MIP. At 15%:15% of SDS:AcOH, although there was even more initial template removal, subsequent re-binding studies showed a decrease in imprinting efficiency (67.9%). Trypsin solutions were also used as a method of template removal. Up to 87.4% of template was reproducibly removed initially; however, the imprinting efficiency was only 20.4%. The high selectivity of the BHb HydroMIP to BHb compared with other structural analogues (namely cytochrome C and myoglobin) was successfully demonstrated.