Howard Hughes Medical Institute, Ithaca, NY, 14853, USA.
Department of Physics & LASSP, Ithaca, NY, 14853, USA.
Nat Commun. 2022 Jan 10;13(1):77. doi: 10.1038/s41467-021-27709-3.
Nanophotonic tweezers represent emerging platforms with significant potential for parallel manipulation and measurements of single biological molecules on-chip. However, trapping force generation represents a substantial obstacle for their broader utility. Here, we present a resonator nanophotonic standing-wave array trap (resonator-nSWAT) that demonstrates significant force enhancement. This platform integrates a critically-coupled resonator design to the nSWAT and incorporates a novel trap reset scheme. The nSWAT can now perform standard single-molecule experiments, including stretching DNA molecules to measure their force-extension relations, unzipping DNA molecules, and disrupting and mapping protein-DNA interactions. These experiments have realized trapping forces on the order of 20 pN while demonstrating base-pair resolution with measurements performed on multiple molecules in parallel. Thus, the resonator-nSWAT platform now meets the benchmarks of a table-top precision optical trapping instrument in terms of force generation and resolution. This represents the first demonstration of a nanophotonic platform for such single-molecule experiments.
纳米光子镊子代表了新兴的平台，具有在芯片上对单个生物分子进行并行操作和测量的巨大潜力。然而，捕获力的产生对其更广泛的应用构成了重大障碍。在这里，我们提出了一种基于共振腔的纳米光子驻波阵列陷阱（resonator-nSWAT），它具有显著的力增强效果。该平台将临界耦合谐振器设计与 nSWAT 集成，并采用了一种新颖的陷阱重置方案。nSWAT 现在可以执行标准的单分子实验，包括拉伸 DNA 分子以测量它们的力-延伸关系、解开 DNA 分子、破坏和绘制蛋白质-DNA 相互作用。这些实验实现了 20pN 量级的捕获力，同时在多个分子上进行并行测量，实现了碱基对分辨率。因此，在力产生和分辨率方面，谐振腔-nSWAT 平台现在达到了台式精密光学捕获仪器的基准。这代表了第一个用于此类单分子实验的纳米光子平台的演示。
