Open AccessDark-field optical tweezers for nanometrology of metallic nanoparticles
Author(s) -
Kellie Pearce,
Fan Wang,
Peter J. Reece
Publication year - 2011
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.19.025559
Subject(s) - optical tweezers , nanometrology , materials science , surface plasmon resonance , nanoparticle , optics , tweezers , dark field microscopy , particle (ecology) , nanotechnology , microscopy , physics , atomic force microscopy , oceanography , geology
Applications of metallic nanoparticles are based on their strongly size-dependent optical properties. We present a method for combining optical tweezers with dark field microscopy that allows measurement of localised surface plasmon resonance (LSPR) spectra on single isolated nanoparticles without compromising the strength of the optical trap. Using this spectroscopic information in combination with measurements of trap stiffness and hydrodynamic drag, allows us to determine the dimensions of the trapped nanoparticles. A relationship is found between the measured diameters of the particles and the peak wavelengths of their spectra. Using this method we may also resolve complex spectra of particle aggregation and interactions within the tweezers.