Stable optical trapping and sensitive characterization of nanostructures using standing- wave Raman tweezers
Loading...
Files
Date
2017-02-17
Access
Authors
Wu, Mu-ying
Ling, Dong-xiong
Ling, Lin
Li, William
Li, Yong-qing
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Optical manipulation and label-free characterization of nanoscale structures open up new possibilities for assembly and control of nanodevices and biomolecules. Optical tweezers integrated with Raman spectroscopy allows analyzing a single trapped particle, but is generally less effective for individual nanoparticles. The main challenge is the weak gradient force on nanoparticles that is insufficient
to overcome the destabilizing effect of scattering force and Brownian motion. Here, we present
standing-wave Raman tweezers for stable trapping and sensitive characterization of single isolated nanostructures with a low laser power by combining a standing-wave optical trap with confocal Raman spectroscopy. This scheme has stronger intensity gradients and balanced scattering forces, and thus can be used to analyze many nanoparticles that cannot be measured with single-beam Raman tweezers, including individual single-walled carbon nanotubes (SWCNT), graphene flakes, biological particles, SERS-active metal nanoparticles, and high-refractive semiconductor nanoparticles. This would enable sorting and characterization of specific SWCNTs and other nanoparticles based on their increased Raman fingerprints.
Description
Keywords
Citation
DOI
10.1038/srep42930