Novel highly sensitive conductometric biosensor based on arginine deiminase from Mycoplasma hominis for determination of arginine
Kseniia Berketa, Olga Saiapina, Lyubov Fayura, Andriy А. Sibirny, S. V. Dzyadevych, О. О. Солдаткін
Abstract
Herein, a novel arginine-sensitive conductometric biosensor based on a recombinant arginine deiminase (ADI) from Mycoplasma hominis, which was produced in E. coli, was developed for the detection of L-arginine. To develop the biosensor, ADI was immobilized by crosslinking with glutaraldehyde on the sensitive surface of the interdigitated electrodes of the conductometric transducer. In this work, the optimal conditions of enzyme immobilization (enzyme concentration and time of immobilization) were determined. The influence of solution parameters (pH, ionic strength and buffer capacity) on the biosensor sensitivity was studied. The biosensor showed high selectivity in the presence of non-target compounds. The main analytical characteristics of the developed biosensor were as follows: linear range – 20–750 μM, limit of detection – 2 µM, response time – 1–1.5 min. The biosensor demonstrated high stability at different storage conditions and was more stable when stored dry at − 18 ºC. Finally, the developed biosensor was used for quantification of arginine in dietary supplements; the results obtained were in good correlation with the results of ion chromatography.