Faculty of Fundamental Sciences, Vilnius Gediminas Technical University, Saulėtekio al. 11, LT-10223, Vilnius, Lithuania.
Institute of Biochemistry, Life Sciences Center, Vilnius University, Saulėtekio al. 7, LT-10257, Vilnius, Lithuania.
Biosens Bioelectron. 2020 Sep 15;164:112338. doi: 10.1016/j.bios.2020.112338. Epub 2020 May 30.
Every electrochemical biosensor uses two or three electrode setup, which involves sensing electrode for a specific reaction, metal/salt reference electrode (i.e., Ag/AgCl or Hg/HgCl) for the control of the potential and, is some cases, counter electrode for the compensation of the current. This setup has significant flaws related to metal/salt reference electrodes: they are bulky and difficult to miniaturize, leak electrolyte to the medium, lose the ability to define the electrochemical potential precisely in time, consequently, have to be updated or replaced. This causes problems when the biosensor cannot be easily replaced (e.g., implanted electronics). Here we present a fully enzymatic real-time glucose monitoring system capable of referencing its own electrochemical potential. Using sensing electrode composed of wired glucose dehydrogenase and enzymatic reference electrode composed of wired laccase we have created a stable and accurate electrode system, which measured fluxes in concentration of glucose in a physiological range (3-8 mM), and demonstrated performance of the designed system in undiluted human serum. In addition, our designed enzymatic reference electrode is universal and may be applied for other biosensors, thus open possibilities for the new generation of implantable devices for healthcare monitoring.
每种电化学生物传感器都使用两个或三个电极设置，其中包括用于特定反应的传感电极、用于控制电位的金属/盐参比电极（例如 Ag/AgCl 或 Hg/HgCl），在某些情况下还有用于补偿电流的对电极。这种设置与金属/盐参比电极有很大的缺陷：它们体积庞大且难以小型化，会向介质中泄漏电解质，失去准确及时定义电化学电位的能力，因此必须进行更新或更换。当生物传感器不容易更换时（例如植入式电子设备），这就会导致问题。在这里，我们提出了一种完全酶促实时葡萄糖监测系统，能够参考其自身的电化学电位。使用由有线葡萄糖脱氢酶组成的传感电极和由有线漆酶组成的酶参考电极，我们创建了一个稳定且精确的电极系统，该系统可在生理范围内（3-8 mM）测量葡萄糖浓度的通量，并在未稀释的人血清中证明了设计系统的性能。此外，我们设计的酶参考电极具有通用性，可用于其他生物传感器，从而为医疗保健监测的新一代植入式设备开辟了可能性。
