Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, NC, 27599, USA.
Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, NC, 27599, USA.
Biosens Bioelectron. 2024 Jun 15;254:116197. doi: 10.1016/j.bios.2024.116197. Epub 2024 Mar 7.
Herein, we present a proof-of-concept of an enzyme sensor combining closed bipolar electrode system with quasi-direct electron transfer (DET) type enzyme. The closed bipolar electrode system was tested using cyclic voltammetry, with L-lactate as a model substrate. L-Lactate was detected through measurement of the change in junction potential across the bipolar electrode. This change in junction potential was caused by reduction of amino reactive phenazine ethosulfate conjugated to Aerococcus vilidans derived engineered L-lactate oxidase (AvLOx) which shows a quasi-DET signal. Using the closed bipolar electrode system allowed simultaneous measuring using cyclic voltammetry and open circuit potential (OCP) and achieved a limit of detection of 400 μM and 76.2 μM lactate respectively. The sensor was then demonstrated to perform with equivalent sensitivity using OCP across varying surface areas. To the best of our knowledge this is the first time a closed bipolar electrode system has been used with an enzyme which is capable of quasi-direct or direct electron transfer. This work can be expanded further to other enzymes capable of directly altering the junction potential of an electrode surface.
在这里，我们提出了一种将封闭双极电极系统与准直接电子转移（DET）型酶相结合的酶传感器的概念验证。使用循环伏安法对封闭双极电极系统进行了测试，以 L-乳酸作为模型底物。通过测量双极电极之间结电位的变化来检测 L-乳酸。这种结电位的变化是由与 Aerococcus vilidans 衍生的工程化 L-乳酸氧化酶（AvLOx）结合的氨基反应性吩嗪乙硫酸酯的还原引起的，AvLOx 显示出准 DET 信号。使用封闭双极电极系统可以同时使用循环伏安法和开路电位（OCP）进行测量，分别实现了 400 μM 和 76.2 μM 乳酸的检测限。然后证明该传感器使用不同表面积的 OCP 具有等效的灵敏度。据我们所知，这是首次将能够进行准直接或直接电子转移的酶与封闭双极电极系统一起使用。这项工作可以进一步扩展到其他能够直接改变电极表面结电位的酶。
