NEW CREATININE-SENSITIVE BIOSENSOR BASED ON CREATININE DEIMINASE ADSORBED ON SILICALITE

The work describes the development and adaptation of a new creatinine-sensitive biosensor based on pH-sensitive field-effect transistors and immobilized creatinine deiminase adsorbed on silicalite-modified electrodes. In order to analyze the potential of the new biosensor, most of the analytical characteristics were analyzed in comparison with the biosensor based on the traditional enzyme immobilization method. Covalent crosslinking of creatinine deiminase in saturated glutaraldehyde vapors was used as a comparison method. It has been shown that adsorption on silicalite significantly improves the main analytical parameters of the biosensor, compared to the control method. Also in the work, the reproducibility of the signals of the proposed biosensor and its stability during storage using an optimized buffer composition with the addition of stabilizers and preservatives were investigated. The effect of different concentrations of sodium chloride and protein (as the most influential components of blood serum) on the performance of a new creatinine-sensitive biosensor was tested. The developed and adapted biosensor based on creatinine deiminase adsorbed on silicalite is effective for quantitative detection of creatinine in real biological samples of patients with renal failure, such as blood serum and dialysis fluid.