Špačková Barbora, Šípová-Jungová Hana, Käll Mikael, Fritzsche Joachim, Langhammer Christoph
Department of Physics, Chalmers University of Technology, 412 96 Göteborg, Sweden.
ACS Sens. 2021 Jan 22;6(1):73-82. doi: 10.1021/acssensors.0c01774. Epub 2020 Dec 28.
Detection of small amounts of biological compounds is of ever-increasing importance but also remains an experimental challenge. In this context, plasmonic nanoparticles have emerged as strong contenders enabling label-free optical sensing with single-molecule resolution. However, the performance of a plasmonic single-molecule biosensor is not only dependent on its ability to detect a molecule but equally importantly on its efficiency to transport it to the binding site. Here, we present a theoretical study of the impact of downscaling fluidic structures decorated with plasmonic nanoparticles from conventional microfluidics to nanofluidics. We find that for ultrasmall picolitre sample volumes, nanofluidics enables unprecedented binding characteristics inaccessible with conventional microfluidic devices, and that both detection times and number of detected binding events can be improved by several orders of magnitude. Therefore, we propose nanoplasmonic-nanofluidic biosensing platforms as an efficient tool that paves the way for label-free single-molecule detection from ultrasmall volumes, such as single cells.
检测少量生物化合物的重要性日益增加，但仍是一项实验挑战。在此背景下，等离子体纳米颗粒已成为有力的竞争者，能够实现具有单分子分辨率的无标记光学传感。然而，等离子体单分子生物传感器的性能不仅取决于其检测分子的能力，同样重要的是还取决于将分子传输到结合位点的效率。在此，我们对用等离子体纳米颗粒修饰的流体结构从传统微流体缩小到纳米流体的影响进行了理论研究。我们发现，对于超小皮升的样品体积，纳米流体能够实现传统微流体装置无法达到的前所未有的结合特性，并且检测时间和检测到的结合事件数量都可以提高几个数量级。因此，我们提出纳米等离子体 - 纳米流体生物传感平台作为一种高效工具，为从超小体积（如单细胞）进行无标记单分子检测铺平道路。
