Poly(acrylamide)-co-poly(hydroxyethyl)methacrylate-co-poly(cyclohexyl methacrylate) hydrogel platform for stability, storage and biocatalytic applications of urease.

In our present work, an explicit crosslinked thermo-responsive hydrogel platform has been developed, by using polyacrylamide (PAAm), poly(2-hydroxyethyl methacrylate) (PHEMA) and poly(cyclohexyl methacrylate) (PCHMA), and then coupled with urease to yield bioconjugates (BCs). Synergic effect of these polymer units provides thermoresponsive nature, optimum crosslinking with desired swelling behaviour, and stability and improved catalytic to Urease in the resultant BCs. Synthesis of the terpolymer has been achieved by employing HEMA (monomer as well as crosslinker), instead of using the conventional crosslinkers, through free radical solution polymerization technique. Various grades of TRPUBs have been fabricated by varying HEMA and CHMA contents while keeping fixed amounts of AAm. Further, the structural analysis of BCs has been done by fourier transform infra-red spectroscopic study and their thermal stabilities have been studied by thermogravimetric analysis. Urea present in TRPUBs has beenanalysed for its hydrolysis atdifferent temperatures viz., 25 °C, 45 °C and 70 °C. Further, the effect of crosslinking, temperature and reaction time on catalytic activities of TRPUBs has been studied. TRPUBs grades have showna maximum swelling capacity up to 5200 %; excellent catalytic activity even at 70 °C; and 85 % activity retention after 18 days storage in buffer medium.