АДАПТАЦІЯ МОНОФЕРМЕНТНОГО КОНДУКТОМЕТРИЧНОГО БІОСЕНСОРА ДЛЯ ВИСОКОЧУТЛИВОГО ВИЗНАЧЕННЯ АРГІНІНУ В ДІЄТИЧНИХ ДОБАВКАХ

The work describes the development of a monoenzyme conductometric biosensor for the determination of arginine in pharmaceutical samples. The biosensor was created by immobilizing recombinant arginine deiminase (ADI) on electrodes using covalent cross linking in glutaraldehyde vapours. To achieve maximum sensitivity, the influence of the working buffer solution parameters, such as pH, buffer capacity, ionic strength, temperature, and protein concentration, on the operation of the biosensor was investigated. The analytical characteristics, signal reproducibility, and storage stability of the biosensor with the optimized buffer solution were studied. To test the biosensor, arginine in food additives was determined using the standard addition biosensor method. The work shows that the results correlate well with ion-exchange chromatography and enzymatic spectrophotometric analysis. The influence of different sample preparation options on the accuracy of arginine determination was also studied. The biosensor is effective for the accurate determination of arginine in dietary supplements intended to correct its deficiency.