Hong Yifeng, Ye Fan, Gao Xiang, Inman James T, Wang Michelle D
Department of Electrical and Computer Engineering, Cornell University, Ithaca, NY 14853, USA.
Howard Hughes Medical Institute, Cornell University, Ithaca, NY 14853, USA.
Sci Adv. 2024 Dec 13;10(50):eadr4519. doi: 10.1126/sciadv.adr4519.
The angular optical trap (AOT) is a powerful technique for measuring the DNA topology and rotational mechanics of fundamental biological processes. Realizing the full potential of the AOT requires rapid torsional control of these processes. However, existing AOT quartz cylinders are limited in their ability to meet the high rotation rate requirement while minimizing laser-induced photodamage. In this work, we present a trapping particle design to meet this challenge by creating small metamaterial elliptical cylinders with tunable trapping force and torque properties. The optical torque of these cylinders arises from their shape anisotropy, with their optical properties tuned via multilayered SiO and SiN deposition. We demonstrate that these cylinders can be rotated at about three times the rate of quartz cylinders without slippage while enhancing the torque measurement resolution during DNA torsional elasticity studies. This approach opens opportunities for previously inaccessible rotational studies of DNA processing.
角向光阱（AOT）是一种用于测量DNA拓扑结构和基本生物过程旋转力学的强大技术。要充分发挥AOT的潜力，需要对这些过程进行快速扭转控制。然而，现有的AOT石英圆柱体在满足高旋转速率要求同时将激光诱导的光损伤降至最低的能力方面存在局限性。在这项工作中，我们提出了一种捕获粒子设计，通过制造具有可调捕获力和扭矩特性的小型超材料椭圆圆柱体来应对这一挑战。这些圆柱体的光扭矩源于其形状各向异性，其光学特性通过多层SiO和SiN沉积进行调节。我们证明，在DNA扭转弹性研究中，这些圆柱体能够以大约石英圆柱体三倍的速率旋转而不发生滑动，同时提高扭矩测量分辨率。这种方法为以前无法进行的DNA加工旋转研究开辟了机会。
