Far-field plasmonic resonance enhanced nanoparticle image velocimetry within a microchannel

In this paper, a novel far-field plasmonic resonance enhanced nanoparticle-seeded particle image velocimetry has been demonstrated to measure the velocity profile in a microchannel. Chemically synthesized silver nanoparticles have been used to seed the flow in the microchannel. By using discrete dipole approximation, plasmonic resonance enhanced light scattering has been calculated for spherical silver nanoparticles with diameters ranging from 15 to 200 nm. Optimum scattering wavelength is specified for the nanoparticles in two media: water and air. The diffraction-limited plasmonic resonance enhanced images of silver nanoparticles at different diameters have been recorded and analyzed. By using standard particle image velocimetry techniques, the velocity profile within the microchannel has been determined from the images.