Dick Jeffrey E, Hilterbrand Adam T, Strawsine Lauren M, Upton Jason W, Bard Allen J
Center for Electrochemistry, Department of Chemistry, The University of Texas at Austin, Austin, TX 78712;
Department of Molecular Biosciences, LaMontagne Center for Infectious Disease, and Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712.
Proc Natl Acad Sci U S A. 2016 Jun 7;113(23):6403-8. doi: 10.1073/pnas.1605002113. Epub 2016 May 23.
We report the specific collision of a single murine cytomegalovirus (MCMV) on a platinum ultramicroelectrode (UME, radius of 1 μm). Antibody directed against the viral surface protein glycoprotein B functionalized with glucose oxidase (GOx) allowed for specific detection of the virus in solution and a biological sample (urine). The oxidation of ferrocene methanol to ferrocenium methanol was carried out at the electrode surface, and the ferrocenium methanol acted as the cosubstrate to GOx to catalyze the oxidation of glucose to gluconolactone. In the presence of glucose, the incident collision of a GOx-covered virus onto the UME while ferrocene methanol was being oxidized produced stepwise increases in current as observed by amperometry. These current increases were observed due to the feedback loop of ferrocene methanol to the surface of the electrode after GOx reduces ferrocenium methanol back to ferrocene. Negative controls (i) without glucose, (ii) with an irrelevant virus (murine gammaherpesvirus 68), and (iii) without either virus do not display these current increases. Stepwise current decreases were observed for the prior two negative controls and no discrete events were observed for the latter. We further apply this method to the detection of MCMV in urine of infected mice. The method provides for a selective, rapid, and sensitive detection technique based on electrochemical collisions.
我们报告了单个鼠巨细胞病毒（MCMV）与铂超微电极（UME，半径为1μm）的特异性碰撞。针对用葡萄糖氧化酶（GOx）功能化的病毒表面蛋白糖蛋白B的抗体能够特异性检测溶液和生物样品（尿液）中的病毒。在电极表面将二茂铁甲醇氧化为二茂铁鎓甲醇，二茂铁鎓甲醇作为GOx的共底物催化葡萄糖氧化为葡萄糖酸内酯。在存在葡萄糖的情况下，当二茂铁甲醇被氧化时，覆盖有GOx的病毒与UME的入射碰撞通过安培法观察到电流逐步增加。观察到这些电流增加是由于在GOx将二茂铁鎓甲醇还原回二茂铁后，二茂铁甲醇反馈到电极表面。阴性对照（i）无葡萄糖，（ii）有无关病毒（鼠γ疱疹病毒68），以及（iii）无任何病毒均未显示这些电流增加。前两个阴性对照观察到电流逐步下降，而后者未观察到离散事件。我们进一步将该方法应用于检测感染小鼠尿液中的MCMV。该方法提供了一种基于电化学碰撞的选择性、快速且灵敏的检测技术。
