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 2 and Si 3 N 4 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.

中文翻译：

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用于单个 DNA 分子旋转机械研究的可调椭圆柱体


角度光阱 （AOT） 是一种强大的技术，用于测量基本生物过程的 DNA 拓扑和旋转力学。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转速要求的同时最大限度地减少激光诱导的光损伤的能力有限。在这项工作中，我们提出了一种捕集粒子设计，通过创建具有可调捕集力和扭矩特性的小型超材料椭圆柱体来应对这一挑战。这些圆柱体的光扭矩来自其形状各向异性，其光学特性通过多层 SiO 2 和 Si 3 N 4 沉积进行调整。我们证明，这些圆柱体可以以大约三倍于石英圆柱体的速率旋转而不会打滑，同时在 DNA 扭转弹性研究中提高了扭矩测量分辨率。这种方法为以前无法获得的 DNA 加工旋转研究提供了机会。