A NOVEL ELECTROCHEMICAL BIOSENSOR BASED ON CREATININE DEIMINASE FOR CREATININE ANALYSIS

This work presents the development of a new electrochemical biosensor based on creatinine deiminase for the determination of creatinine concentration in biological samples. The optimal method for immobilizing bioselective elements on the electrode surface was selected, specifically the covalent binding of creatinine deiminase in a BSA matrix using glutaraldehyde. The biosensors prepared in this way exhibited the highest sensitivity to creatinine and high reproducibility in the fabrication of biomembranes. The biosensor demonstrated a low limit of detection of creatinine, high signal stability (RSD = 3%), significant storage stability, and a wide linear range, enabling the detection of both normal and pathological creatinine concentrations in biological fluids. The study also investigated the influence of working solution parameters, such as ionic strength, buffer capacity, pH, and protein content, on the biosensor’s performance. The main analytical characteristics of the proposed electrochemical biosensor indicate its potential use for monitoring creatinine concentration in biological samples.