Extraction and immobilization of the urease enzyme in polyvinylpyrrolidone films: applications in biosensors

Enzymes play a fundamental role in the manufacture of biosensors, acting as biological recognition elements due to their sensitivity and selectivity in the reactions they catalyze. Among them, urease stands out as an efficient enzyme found in nature, whose function involves the hydrolysis of urea. This enzyme has been used when extracted from legume seeds, as well as various bacteria and fungi. The objective of this study was the extraction and immobilization of the urease enzyme in polyvinylpyrrolidone (PVP) films. Crude jack bean extracts were prepared at concentrations of 15, 25 and 35% in PBS/PVP, centrifuged and refrigerated. Subsequently, aliquots of each solution were applied to plates to form films, being characterized by enzymatic activity, pH, FTIR and UV-vis. The affinity with urea was evidenced by enzymatic activity, pH and UV-vis, compatible with the Michaelis-Menten model. In FTIR, the polypeptide bands characteristic of the amino acids present in the structure of the enzymes, such as those of amides I, II and III, were confirmed.