Sülzle Jenny, Yang Wayne, Shimoda Yuta, Ronceray Nathan, Mayner Eveline, Manley Suliana, Radenovic Aleksandra
Institute of Physics and Institute of Bioengineering, Laboratory of Experimental Biophysics (LEB), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, 1015, Switzerland.
Institute of Bioengineering, Laboratory of Nanoscale Biology (LBEN), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, 1015, Switzerland.
ACS Photonics. 2024 Jan 10;11(2):737-744. doi: 10.1021/acsphotonics.3c01604. eCollection 2024 Feb 21.
Two-dimensional (2D) materials offer potential as substrates for biosensing devices, as their properties can be engineered to tune interactions between the surface and biomolecules. Yet, not many methods can measure these interactions in a liquid environment without introducing labeling agents such as fluorophores. In this work, we harness interferometric scattering (iSCAT) microscopy, a label-free imaging technique, to investigate the interactions of single molecules of long dsDNA with 2D materials. The millisecond temporal resolution of iSCAT allows us to capture the transient interactions and to observe the dynamics of unlabeled DNA binding to a hexagonal boron nitride (hBN) surface in solution for extended periods (including a fraction of 10%, of trajectories lasting longer than 110 ms). Using a focused ion beam technique to engineer defects, we find that DNA binding affinity is enhanced at defects; when exposed to long lanes, DNA binds preferentially at the lane edges. Overall, we demonstrate that iSCAT imaging is a useful tool to study how biomolecules interact with 2D materials, a key component in engineering future biosensors.
二维（2D）材料有望成为生物传感设备的底物，因为其特性可通过工程设计来调节表面与生物分子之间的相互作用。然而，在不引入诸如荧光团等标记剂的情况下，能够在液体环境中测量这些相互作用的方法并不多。在这项工作中，我们利用无标记成像技术——干涉散射（iSCAT）显微镜，来研究长双链DNA单分子与二维材料之间的相互作用。iSCAT的毫秒级时间分辨率使我们能够捕捉瞬态相互作用，并长时间观察未标记的DNA在溶液中与六方氮化硼（hBN）表面结合的动力学过程（包括10%的轨迹持续时间超过110毫秒）。通过使用聚焦离子束技术制造缺陷，我们发现DNA在缺陷处的结合亲和力增强；当暴露于长通道时，DNA优先在通道边缘结合。总体而言，我们证明了iSCAT成像对于研究生物分子如何与二维材料相互作用是一种有用的工具，而二维材料是未来生物传感器工程的关键组成部分。
