Flow-dependent double-nanohole optical trapping of 20 nm polystyrene nanospheres

Abstract

We study the influence of fluid flow on the ability to trap optically a 20 nm polystyrene particle from a stationary microfluidic environment and then hold it against flow. Increased laser power is required to hold nanoparticles as the flow rate is increased, with an empirical linear dependence of 1 μl/(min×mW). This is promising for the delivery of additional nanoparticles to interact with a trapped nanoparticle; for example, to study protein-protein interactions, and for the ability to move the trapped particle in solution from one location to another.

Optical trapping and manipulation of micrometer and submicrometer particles

“…Subwavelength aperture diffraction is, subject to debate, another area where plasmonics may play a role. Previously [126] 2012, Scientific Reports)…”

Plasmofluidics: Merging Light and Fluids at the Micro-/Nanoscale

“…Gordon and co‐workers employed double‐nanoholes on an Au thin film to trap dielectric nanoparticles with diameters down to 12 nm with a reduced light intensity . Recently, using the same plasmonic substrates, the Gordon group has successfully trapped a single protein and protein–antibody pairs …”

“…For example, Martin and co‐workers have achieved the simultaneous trapping and sensing of 10 nm particles with plasmonic nanoantennas . Based on the sensitivity of light transmission through the nanoapertures to the movement of nanoparticles, SIBA‐based plasmonic tweezers have also enabled simultaneous trapping and sensing …”

“…[ 77 ] Recently, using the same plasmonic substrates, the Gordon group has successfully trapped a single protein and protein-antibody pairs. [78][79][80][81] Beyond the static trapping, the 3D manipulation of sub-100 nm dielectric objects has also been achieved with SIBA. [ 82 ] Using an optical fi ber probe with a bowtie nano-aperture at the tip for the SIBA-based trapping, Quidant and coworkers have successfully trapped and manipulated sub-100 nm dielectric objects in 3D within a microfl uidic chamber ( Figure 9 ).…”

“…[ 70,90 ] Based on the sensitivity of light transmission through the nanoapertures to the movement of nanoparticles, SIBA-based plasmonic tweezers have also enabled simultaneous trapping and sensing. [75][76][77][78][79][80]91 ]…”