Stability is one of the most important characteristics of the potentiometric urea biosensors; however, it has rarely been discussed in previous literature. In this article, the stability of the potentiometric urea biosensor based on the urease-Ag NPs/RuO2 sensing film was studied. Using the voltage–time ( VV – TT ) measurement system, the stability was verified by analyzing the biosensor’s reproducibility, repeatability, long-term measurement, and effect of temperature. Based on the results of this study, the proposed potentiometric urea biosensor had good reproducibility [relative standard deviation (RSD) was 2.23%] and repeatability (RSD was 1.16%). The urease-Ag NPs/RuO2 sensing film still has 90% initial sensitivity after 15 days of storage at room temperature. Moreover, the proposed urea biosensor was integrated into the microfluidic system and the remote measurement system. The sensing characteristics of the potentiometric urea biosensor under different flow rates (1.4–7.0 μL\mu \text{L} /min, 0–30 μL\mu \text{L} /min) were studied. In the remote measurement, the average sensitivity was 45.75 mV/decade and the linearity was 0.986.

中文翻译：

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微流控系统下电位式尿素生物传感器的稳定性分析及远程测量


稳定性是电位尿素生物传感器最重要的特性之一；然而，在以前的文献中很少对此进行讨论。本文研究了基于脲酶-Ag NPs/RuO2传感膜的电位尿素生物传感器的稳定性。采用电压-时间（VV-TT）测量系统，通过分析生物传感器的再现性、重复性、长期测量以及温度的影响来验证稳定性。基于本研究的结果，所提出的电位尿素生物传感器具有良好的重现性[相对标准偏差（RSD）为2.23%]和重复性（RSD为1.16%）。脲酶-Ag NPs/RuO2传感膜在室温下保存15天后仍具有90%的初始灵敏度。此外，所提出的尿素生物传感器被集成到微流体系统和远程测量系统中。研究了电位尿素生物传感器在不同流量（1.4~7.0 μL\mu \text{L} /min、0~30 μL\mu \text{L} /min）下的传感特性。远程测量中，平均灵敏度为45.75 mV/decade，线性度为0.986。