Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA; Lineberger Comprehensive Cancer Center, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
Biosens Bioelectron. 2021 Apr 15;178:112997. doi: 10.1016/j.bios.2021.112997. Epub 2021 Jan 17.
Continuous monitoring of biological metabolites of interest necessitates sensors that are robust, versatile, miniaturizable, and reliable. Electrochemical biosensors have dominated the field of biosensors for decades due to their robust and inexpensive nature. Classically, these sensors use amperometric and voltammetric methods as the sensing modality. One of the greatest limitations with these methods is the dependence of the signal (current, i) on the electrode size, which can change with respect to time due to fouling. Here, we present open circuit potential, an electrochemical technique that is relatively insensitive to electrode size, as a reliable alternative to amperometric and voltammetric techniques for monitoring metabolites of interest. The sensor operates by trapping an oxidase enzyme in a chitosan hydrogel. The oxidase enzyme is required for metabolite specificity. When the oxidase enzyme meets its substrate, oxygen is consumed, and hydrogen peroxide is generated. Hydrogen peroxide generation dominates a half reaction at the platinum surface, resulting in a change in potential. Using the above criteria, we demonstrate the efficacy, long lifetime, sensitivity, and ease of fabrication of glucose sensors, and miniaturize the sensors from macro- to microelectrodes. Additionally, we demonstrate the ease with which this platform can be extended to detect other analytes in the form of a galactose sensor. Our results set a foundation for the generalized use of potentiometric sensors for a broad range of metabolites and applications.
连续监测感兴趣的生物代谢物需要具有稳健、多功能、小型化和可靠的传感器。由于其稳健和廉价的性质，电化学生物传感器在生物传感器领域占据主导地位已有数十年。经典地，这些传感器使用电流和伏安法作为传感模式。这些方法的最大局限性之一是信号（电流，i）对电极尺寸的依赖性，由于污垢，电极尺寸可能随时间变化。在这里，我们提出开路电位，这是一种相对不依赖于电极尺寸的电化学技术，作为监测感兴趣的代谢物的电流和伏安法的可靠替代方法。该传感器通过将氧化酶酶捕获在壳聚糖水凝胶中来工作。氧化酶酶是代谢物特异性所必需的。当氧化酶酶遇到其底物时，氧气被消耗，过氧化氢被生成。过氧化氢的生成在铂表面的半反应中占主导地位，导致电位变化。使用上述标准，我们证明了葡萄糖传感器的功效、长寿命、灵敏度和易于制造，并且将传感器从小型化到微型化。此外，我们证明了该平台易于扩展为以半乳糖传感器的形式检测其他分析物。我们的结果为广泛使用电位传感器来监测广泛的代谢物和应用奠定了基础。
