Freko Sebastian, Weiß Lennart J K, Simmel Friedrich C, Wolfrum Bernhard
Neuroelectronics, Munich Institute of Biomedical Engineering, Department of Electrical Engineering, School of Computation, Information and Technology, Technical University of Munich, Garching 85748, Germany.
Department of Medicine I, Cardiology, Angiology, Pneumology, Klinikum rechts der Isar, Technical University of Munich, TUM School of Medicine and Health, Munich 81675, Germany.
ACS Sens. 2025 Jun 27;10(6):3840-3853. doi: 10.1021/acssensors.5c00064. Epub 2025 Jun 14.
Direct single-impact electrochemistry is a rapidly evolving analytical method based on the collision of redox-active species, such as silver nanoparticles (AgNPs), with a biased microelectrode. The collision results in distinct current spikes due to partial or complete oxidation of a particle. In recent years, this technique has been applied in various biosensing strategies as a "digital" readout technique. It offers the quantification of analytes using discrete signals, as opposed to conventional amplitude-based methods. In this review, we explore the latest advancements in direct single-impact electrochemistry for biosensing applications. In addition, we summarize the key factors influencing the "digital" readout performance and their interrelationships, including particle size and corona, electrode size and potential, electrolyte composition, particle mass transport toward the electrode, and data acquisition. Considering recent experimental developments and theoretical principles, we have identified guidelines that are expected to facilitate and accelerate the development of novel direct impact-based sensing platforms, particularly for point-of-care (POC) applications.
直接单碰撞电化学是一种基于氧化还原活性物质（如银纳米颗粒（AgNPs））与偏置微电极碰撞的快速发展的分析方法。由于颗粒的部分或完全氧化，碰撞会产生明显的电流尖峰。近年来，该技术作为一种“数字”读出技术已应用于各种生物传感策略中。与传统的基于幅度的方法不同，它使用离散信号对分析物进行定量。在本综述中，我们探讨了直接单碰撞电化学在生物传感应用方面的最新进展。此外，我们总结了影响“数字”读出性能的关键因素及其相互关系，包括颗粒大小和电晕、电极大小和电位、电解质组成、颗粒向电极的质量传输以及数据采集。考虑到最近的实验进展和理论原理，我们确定了一些指导方针，有望促进和加速新型基于直接碰撞的传感平台的开发，特别是用于即时检测（POC）应用。
