Department of Electrical and Computer Engineering, University of Victoria, Victoria, British Columbia V8W 3P6, Canada.
Nano Lett. 2011 Sep 14;11(9):3763-7. doi: 10.1021/nl201807z. Epub 2011 Aug 15.
Optical tweezers have found many applications in biology, but for reasonable intensities, conventional traps are limited to particles >100 nm in size. We use a double-nanohole in a gold film to experimentally trap individual nanospheres, including 20 nm polystyrene spheres and 12 nm silica spheres, at a well-defined trapping point. We present statistical studies on the trapping time, showing an exponential dependence on the optical power. Trapping experiments are repeated for different particles and several nanoholes with different gap dimensions. Unusually, smaller particles can be more easily trapped than larger ones with the double-nanohole. The 12 nm silica sphere has a size and a refractive index comparable to the smallest virus particles and has a spherical shape which is the worst case scenario for trapping.
光学镊子在生物学中有许多应用，但对于合理的强度，传统的陷阱仅限于大于 100nm 的颗粒。我们使用金膜中的双纳米孔在实验中捕获单个纳米球，包括 20nm 的聚苯乙烯球和 12nm 的二氧化硅球，在一个明确定义的捕获点。我们对捕获时间进行了统计研究，显示出与光功率的指数依赖性。我们对不同的粒子和不同间隙尺寸的几个纳米孔进行了重复的捕获实验。不同寻常的是，双纳米孔可以更容易地捕获较小的粒子，而不是较大的粒子。12nm 的二氧化硅球的大小和折射率与最小的病毒粒子相当，并且具有球形，这是捕获的最坏情况。
