Nano‐Optical Tweezers: Methods and Applications for Trapping Single Molecules and Nanoparticles

Optical tweezers were developed in 1970 by Arthur Ashkin as a tool for the manipulation of micron‐sized particles. Ashkin's original design was then adapted for a variety of purposes, such as trapping and manipulation of biological materials[1] and the laser cooling of atoms.[2,3] More recent development has led to nano‐optical tweezers, for trapping particles on the scale of only a few nanometers, and holographic tweezers, which allow for dynamic control of multiple traps in real‐time. These alternatives to conventional optical tweezers have made it possible to trap single molecules and to perform a variety of studies on them. Presented here is a review of recent developments in nano‐optical tweezers and their current and future applications. Nano‐optical tweezers are devices capable of trapping and manipulating objects on the nanometer scale, even single molecules. This capability allows them to be used for a variety of applications in nanotechnology and microbiology. This review discusses nano‐optical tweezing methods and their current and future applications.