Plasmonic tweezers for optical manipulation and biomedical applications

Abstract

<p>Plasmonic tweezers are an emerging research topic because of their breakthrough to the conventional diffraction limit and precise manipulation at nanoscale. Notably, their compatibility with analytical techniques (e.g. fluorescence, surface-enhanced...</p>

Optically-assisted thermophoretic reversible assembly of colloidal particles and E. coli using graphene oxide microstructures

“…In this regard, surface plasmon-based trapping schemes have been demonstrated to be more efficient owing to the strong near-field that is generated around plasmonic nanoparticles upon illumination 18 – 21 . There have been several reports of plasmonics-based optical trapping of particles of different sizes varying from microbeads to quantum dots 22 , 23 . However, due to the short range of plasmonic near-field, large-scale assembly of colloidal particles using plasmonic forces requires either arrays of nanostructures 24 , 25 or continuous thin metal films where propagating surface plasmons (surface plasmon polaritons) can be excited 26 .…”

Photo-assembly of plasmonic nanoparticles: methods and applications

“… 12 This was also realized for single proteins 13 or whole cells. 14 Unfortunately, when using AFM or optical nanotweezers, only a limited number of nano- and micro-objects can be manipulated simultaneously (in many cases only a single object). In this work, we describe various light-induced methods of rearranging plasmonic nanoobjects.…”

Plasmonic Optical Tweezers for Particle Manipulation: Principles, Methods, and Applications

“…Therefore, the so-called plasmonic optical tweezer (POT) is proposed to break through this limitation, while improving the scale of optical force and depth of the potential well. This is achieved by enhancing the gradient and strength of the local electromagnetic field with the assistance of plasmonic structures. , Moreover, it can also be employed in the field of high-resolution and high-throughput manipulation and characterization of micro- and nanoparticles at moderate laser powers. , The basic principle of POT is to combine the idea of nanoplasmonics and optical tweezers . Therefore, nanofilm, array of nanocavities, isolated plasmonic micro- or nanoparticles or plasmon antennas, or other structures are usually involved, , which are easy to fabricate due to the rapid development of nanofabrication techniques. , …”

“…They are also exposed to other external forces, such as the drag force of fluid and Brownian force, which make it even harder to control or trap the targets. For optical force-induced particle sorting or trapping, most of the recent studies are focused on the manipulating of particles in a stagnant or slowly moving fluid environment, ,, which basically means that the optical force only needs to be sufficiently high to suppress the Brownian motion. However, the fluid-flow-induced particle movement or the active particle motion (not induced by fluid drag force), which is essential for the delivery of target objects to the trapping spot, also needs to be considered for the applications of high-throughput sorting or analyzing of particles or cells.…”