Investigation of GOx Stability in a Chitosan Matrix: Applications for Enzymatic Electrodes

Abstract

In this study, we designed a new biosensing membrane for the development of an electrochemical glucose biosensor. To proceed, we used a chitosan-based hydrogel that entraps glucose oxidase enzyme (GOx), and we crosslinked the whole matrix using glutaraldehyde, which is known for its quick and reactive crosslinking behavior. Then, the stability of the designed biosensors was investigated over time, according to different storage conditions (in PBS solution at temperatures of 4 °C and 37 °C and in the presence or absence of glucose). In some specific conditions, we found that our biosensor is capable of maintaining its stability for more than six months of storage. We also included catalase to protect the biosensing membranes from the enzymatic reaction by-products (e.g., hydrogen peroxide). This design protects the biocatalytic activity of GOx and enhances the lifetime of the biosensor.

Recent Advances in Applied Electrochemistry: A Review

“…A glucose biosensor is a device that incorporates a biological recognition element as a sensing component (enzymes, e.g., glucose oxidase (GOx) or glucose dehydrogenase (GDH) and its cofactor). The enzymatic reaction byproducts diffuse through the sensing membrane and are then oxidized or reduced on the electrode surface at a fixed potential that depends on the electrode material [140,141]. Typically, in the case of first-generation enzymatic glucose biosensors, the enzymatic oxidation of glucose by GOx leads to the production of hydrogen peroxide (H 2 O 2 ), which is oxidized at a positive potential of +0.7 V vs. a Ag/AgCl reference electrode or reduced at negative potentials (between −0.2 and 0 V) using mediators that lower the detection potentials and prevent interference problems [142].…”

Special Issue “Feature Papers in Biosensors Section 2022”

“…Biosensors are devices composed of a biorecognition part and of a transduction part. Natural biomolecules such as enzymes [ 1 ], antibodies [ 2 ], DNA strains [ 3 ], bacteria and yeast [ 4 , 5 ], cells and even plant/animal tissues can constitute the recognition part. Synthesized polymers such as MIP (molecularly imprinted polymers) [ 1 ], aptamers and peptides can also be used as recognition part.…”

“…Natural biomolecules such as enzymes [ 1 ], antibodies [ 2 ], DNA strains [ 3 ], bacteria and yeast [ 4 , 5 ], cells and even plant/animal tissues can constitute the recognition part. Synthesized polymers such as MIP (molecularly imprinted polymers) [ 1 ], aptamers and peptides can also be used as recognition part. In this special issue, molecularly imprinted overoxidized polypyrrole doped with copper nanoparticles was used for the electrochemical detection of sulfadiazine [ 6 ].…”

“…When natural biomolecules are used, one of the key points is the maintenance of the activity of the biomolecule after their immobilization on the transducer surface. Achitosan matrix was demonstrated to maintain enzyme activity for a longer period of time [ 1 ]. The stability of non-covalent avidin-biotin binding is widely utilized for anchoring biomolecules, and neutravidin and streptavidin are two commonly used avidin analogues.…”