The determination of the enzymatic activity requires constant and reproducible measuring conditions, therefore highly stable potentiometric biosensor operating on the basis of coupled enzyme reactions is proposed for arginase activity determination. Glassy carbon electrode was covered with polyazulene ion-to-electron transducing layer, which ensured improved stability of the prepared sensor. The sensor’s selectivity was obtained by applying NH₄⁺-selective membrane on the transducing layer, which was further biofunctionalized with urease via covalent immobilization. The immobilized urease served as an auxiliary enzyme in the arginase-urease coupled enzyme assay. Thanks to obtained high stability (low drift coefficient ∼ 0.9 mV/h) and short response time (36 s), the developed urea biosensor enabled continuous monitoring the coupled enzyme reactions indirectly, through measurement the ammonium ion concentration. Arginase activity and Michaelis-Menten constant for arginine-arginase pair under defined experimental conditions, in particular constant concentration of manganese ions, was determined. Mathematical description of the coupled enzyme reactions kinetics is discussed and used to analyse the reactions with auxiliary enzyme immobilized on the electrode surface. The proposed method of determining arginase activity with use of highly stable potentiometric urease-based biosensor, allows obtaining results in the units of absolute arginase activity.

酶活性的测定需要恒定且可重复的测量条件，因此提出了基于偶联酶反应操作的高度稳定的电位生物传感器来测定精氨酸酶活性。玻碳电极上覆盖有聚薁离子电子转换层，保证了制备的传感器的稳定性。传感器的选择性是通过在转导层上应用NH ₄ ^{+选择性膜获得的，}通过脲酶进一步生物功能化。共价固定。固定化脲酶在精氨酸酶-脲酶偶联酶测定中用作辅助酶。由于获得了高稳定性（低漂移系数~0.9 mV / h）和短响应时间（36 s），开发的尿素生物传感器能够通过测量铵离子浓度来间接连续监测耦合酶反应。确定了在限定的实验条件下，特别是恒定浓度的锰离子，精氨酸-精氨酸酶对的精氨酸酶活性和 Michaelis-Menten 常数。讨论了耦合酶反应动力学的数学描述，并用于分析固定在电极表面的辅助酶的反应。使用高度稳定的电位脲酶生物传感器确定精氨酸酶活性的建议方法，