Potentiometric and SERS Detection of Single Nanoparticle Collision Events on a Surface Functionalized Gold Nanoelectrode
Potentiometric and SERS Detection of Single Nanoparticle Collision Events on a Surface Functionalized Gold Nanoelectrode
复制标题
表面功能化金纳米电极上单纳米粒子碰撞事件的电位和 SERS 检测
DOI：
10.1149/1945-7111/ac6245
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发表时间：
2022
影响因子：
3.9
通讯作者：
He, Jin
中科院分区：
文献类型：
--
作者：
Ghimire, Govinda;Pandey, Popular;Guo, Jing;Sarker, Golam Sabbir;Moon, Joong Ho;He, Jin
单实体电化学在超灵敏生物传感应用中具有重要的基础意义和前景。最近，我们已经证明了各种带电纳米粒子可以通过它们在浮动碳纳米电极（CNE）上碰撞事件引起的非氧化还原开路电位（OCP）变化来单独检测。与广泛使用的安培法不同，电位法提供了溶液中不含氧化还原介质的单个纳米级实体的无标记检测。然而，由于碳表面的表面功能化方法有限，CNE在碰撞事件中缺乏分子识别的特异性。因此，我们采用表面功能化金纳米电极（GNE）来克服这一限制。用拉曼报告分子修饰的GNE还实现了表面增强拉曼光谱（SERS）测量。通过同时使用时间分辨OCP和SERS测量，可以更好地理解由“打-跑”型金纳米颗粒（GNP）碰撞事件引起的OCP和SERS信号。此外，通过引入两性离子分子，我们形成了近“隐形”表面，并证明GNPs对GNE表面的非特异性吸附被抑制，允许连续检测撞击-n-运行事件超过30分钟。
Single-entity electrochemistry is of fundamental importance and shows promise for ultrasensitive biosensing applications. Recently, we have demonstrated that various charged nanoparticles can be detected individually based on the non-redox open-circuit potential (OCP) changes induced by their collision events on a floating carbon nanoelectrode (CNE). Unlike the widely used amperometry approach, the potentiometric method provides the label-free detection of individual nanoscale entities without redox mediators in the solution. However, the CNE lacks specificity for molecular recognition during the collision events because of the limited methods of surface functionalization for carbon surfaces. Herein, we used surface-functionalized gold nanoelectrode (GNE) to overcome this limitation of CNE. The GNE modified with Raman reporter molecule also enabled surface-enhanced Raman spectroscopy (SERS) measurements. By using simultaneous time-resolved OCP and SERS measurements, both the OCP and SERS signals induced by the" hit-n-run" type of gold nanoparticle (GNP) collision events can be better understood. Also, by introducing a zwitterionic molecule, we formed near" stealth" surface and demonstrated that the non-specific adsorptions of GNPs to the surface of GNE have been suppressed, allowing continuous detection of hit-n-run events for over 30 min.