Multiplexed Near-Field Optical Trapping Exploiting Anapole States

Abstract

Optical tweezers have had a major impact on bioscience research by enabling the study of biological particles with high accuracy. The focus so far has been on trapping individual particles, ranging from the cellular to the molecular level. However, biology is intrinsically heterogeneous; therefore, access to variations within the same population and species is necessary for the rigorous understanding of a biological system. Optical tweezers have demonstrated the ability of trapping multiple targets in parallel; however, the multiplexing capability becomes a challenge when moving toward the nanoscale. Here, we experimentally demonstrate a resonant metasurface that is capable of trapping a high number of nanoparticles in parallel, thereby opening up the field to large-scale multiplexed optical trapping. The unit cell of the metasurface supports an anapole state that generates a strong field enhancement for low-power near-field trapping; importantly, the anapole state is also more angle-tolerant than comparable resonant modes, which allows its excitation with a focused light beam, necessary for generating the required power density and optical forces. We use the anapole state to demonstrate the trapping of 100’s of 100 nm polystyrene beads over a 10 min period, as well as the multiplexed trapping of lipid vesicles with a moderate intensity of <250 μW/μm2. This demonstration will enable studies relating to the heterogeneity of biological systems, such as viruses, extracellular vesicles, and other bioparticles at the nanoscale.

Plasmonic Dielectric Antennas for Hybrid Optical Nanotweezing And Optothermoelectric Manipulation of Single Nanosized Extracellular Vesicles

“…Its near‐field enhancement has enabled several on‐chip applications, including lasing, [ 41 ] nonlinear optics, [ 42 ] and strong coupling phenomenon. [ 43 ] Trapping using optical anapole states [ 44,45 ] has also been investigated. One disadvantage with prior demonstrations is the lack of an approach to actively transport particles into the trapping site or between antennas.…”

Optical Slot-Assisted Metasurface for IgG Protein Detection

“…Each cell of the array is composed of two dimers, with a thickness of t = 100 nm. These dimers have lengths along the xand y-axes of DC x Λ/2 and DC x Λ, respectively, and are made of amorphous silicon (a-Si:H) with n = 3.6 and losses k ≈ 10 -4 within the operating wavelength range of 700 nm -800 nm [5]. The two dimers are separated along the x-axis by a gap g that supports the optical slot effect (Fig.…”

A Novel Electrokinetic-Based Technique for the Isolation of Circulating Tumor Cells

“…Particle separation/sorting methods using microfluidics devices have attracted considerable attention due to their applications in label-free and contact-free disease diagnosis [1][2][3][4]. Several microfluidic devices have been developed to establish different strategies for the manipulation and isolation of bioparticles based on inertial [5,6], optical [4] magnetophoretic [7], dielectrophoresis (DEP) [8][9][10], thermophoresis [11], and acoustophoretic forces [12].…”

“…Particle separation/sorting methods using microfluidics devices have attracted considerable attention due to their applications in label-free and contact-free disease diagnosis [1][2][3][4]. Several microfluidic devices have been developed to establish different strategies for the manipulation and isolation of bioparticles based on inertial [5,6], optical [4] magnetophoretic [7], dielectrophoresis (DEP) [8][9][10], thermophoresis [11], and acoustophoretic forces [12]. For example, particle manipulation in inertial microfluidics is based on the balance between inertial lift forces and dean forces [13,14], while magnetophoretic particle manipulation is based on controlling the movement of particles by applying an external magnetic field [15].…”