Conducting polymers modulating the catalytic activity of urease in thin composite films

Enzymes immobilized in matrices like conducting polymers (CPs) can form a supramolecular structure with enhanced biosensing performance, which depend on the structural polymer properties. This present paper employed CPs from the classes of thiophenes, fluorenes, phenylenes, and phenylene-vinylenes to immobilize urease as thin films and to investigate the relationship between the film structure and the enzyme activity. The films were assembled by the spin coating technique and characterized by UV-vis, fluorescence, and infrared spectroscopies. The enzymatic activity was estimated with UV-vis spectroscopy. Films containing different CPs presented specific enzyme activities dependent on polymers' size and polydispersity, but these activities were independent of their specific conductivity. Poly (9,9-dioctylfluorene-co-phenylene) (PFPh) presented the lower KM constant (1.52 mM.s(-1)) and was the polymer with lower molecular weight and polydispersity. The results suggested that small and homogeneous size chains increase the enzyme activity, which can be beneficial, generally speaking, for the construction of based-enzyme biosensors with enhanced efficiency.

Automated summary

Enzymes immobilized in matrices like conducting polymers can form a supramolecular structure with enhanced biosensing performance, with the enzyme activity depending on the size and polydispersity of the polymers. Small and homogeneous size chains increase enzyme activity, which can be beneficial for constructing enzyme-based biosensors with enhanced efficiency.