Plasmonic Optical Tweezers toward Molecular Manipulation: Tailoring Plasmonic Nanostructure, Light Source, and Resonant Trapping

Abstract

This Perspective describes recent progress in optical trappings of nanoparticles based on localized surface plasmon. This plasmonic optical trapping has great advantages over the conventional optical tweezers, being potentially applicable for a molecular manipulation technique. We review this novel trapping technique from the viewpoints of (i) plasmonic nanostructure, (ii) the light source for plasmon excitation, and (iii) the polarizability of the trapping target. These findings give us future outlook for plasmonic optical trapping. In addition to a brief review, recent developments on plasmonic optical trapping of soft nanomaterials such as proteins, polymer chains, and DNA will be discussed to point out the important issue for further development on this trapping method. Finally, we explore new directions of plasmonic optical trapping.

Insight into plasmonic hot-electron transfer and plasmon molecular drive: new dimensions in energy conversion and nanofabrication

“…55,56 Using the plasmon-assisted approach, one can manipulate single Au NPs, protein molecules and amino-acid clusters with submicrometer precision. Optical forces provide a powerful bottom-up approach to material fabrication.…”

“…58,66 To realize plasmon-assisted optical trapping, hot spots that exhibit enormous enhancements are a prerequisite. 55,56 For Au nanoisland films, reproducible formation of such hot spots may largely depend on technical ability. This can result in differing optimum trapping strengths depending on the sample.…”

Transmission Spectrum of Asymmetric Nanostructures for Plasmonic Space Propulsion

“…In the particle trapping experiments of the plasmon nano-optical tweezers, symmetric nanostructures are employed [4] because they create symmetric trapping volumes, or potential wells. Therefore, in order to create an asymmetric potential and strong particle acceleration, asymmetric nanostructures are investigated.…”

Characterization of the near-field and convectional transport behavior of micro and nanoparticles in nanoscale plasmonic optical lattices

“…1,2 Plasmonic optical tweezers have drawn much research attention in recent years. [3][4][5] For conventional optical tweezers based on the far-field focusing technique, the spatial confinement of the light field is inherently limited by diffraction, and the magnitude of the trapping force drops dramatically (following an $a 3 law for nanoparticle of radius a) when the particle size is much smaller than the wavelength of the light. 6 Plasmonic-based, near-field optical manipulation has been developed to overcome these diffraction-imposed limitations, and has been successfully applied to trap dielectric and metallic nanoparticles, and bacteria.…”