The presence of polysaccharides, glycerol and polyethyleneimine in the hydrogel enhances the performance of the glucose biosensor

The use of amperometric biosensors has attracted particular attention in recent years, both by researchers and by companies, as they have proven to be low-cost, reliable and very sensitive devices, with a wide range of use in different matrices. The continuous development of amperometric biosensors, since their use involves an enzyme, is specifically aimed at keeping and increasing the catalytic properties of the loaded protein, so as to be able to use the same device over time. The present study aimed to investigate the impact of glycerol and polysaccharides, in presence of polycationic substances, to constitute a hydrogel, in enhancing the enzymatic and analytic performances of a glucose biosensor. Initially, it was possible to verify how the deposition of the starch-based hydrogel, in addition to allowing the electropolymerization of the PPD and the maintenance of its ability to shield the ascorbic acid, did not substantially limit the permeability towards hydrogen peroxide. Moreover, different biosensors designs, loading a mixture containing all the components (alone or in combination) and the enzyme, were tested in order to evaluate the changes of the apparent enzyme kinetic parameters, such as VMAX and KM, and analytical response in terms of LRS, highlighting how the presence of all components (starch, glycerol and PEI) were able to substantially enhance the performance of the biosensors. The surface analysis of the biosensors was performed by scanning electron microscope (SEM). More, it was shown that the same performances were kept unchanged for 7 days, proving the suitability of this biosensor design for a short- and mid-term use. Keywords glucose biosensor, glycerol, starch-based hydrogel, PEI. 10.3390/bios9030095