COMPARISON OF CREATININE DEIMINASE IMMOBILIZATION METHODS FOR DESIGN OF POTENTIOMETRIC BIOSENSORS FOR CREATININE DETECTION

The main analytical characteristics of the potentiometric biosensor based on creatinine deiminase were investigated when working with model samples, and comparison for various enzyme immobilization methods was made. It was found that all sensors are characterized by a similar operating range, response time and high operational stability. At the same time, the sensitivity of the biosensor to creatinine was 2 times higher for the option of immobilization in a drop of glutaraldehyde. Storage stability was high for all immobilization methods, with the exception of immobilization in glutaraldehyde vapors, when the value of the sensor response dropped by 50% after 100 days of storage. The dependences on the experimental conditions were typical for enzyme biosensors and did not depend on the enzyme immobilization method. The linear range of creatinine determination is quite suitable for further work with real blood samples and dialysis fluid when diluted 10 times.