Trapping and Detection of Nanoparticles and Cells Using a Parallel Photonic Nanojet Array

Abstract

In advanced nanoscience, there is a strong desire to trap and detect nanoscale objects with high-throughput, single-nanoparticle resolution and high selectivity. Although emerging optical methods have enabled the selective trapping and detection of multiple micrometer-sized objects, it remains a great challenge to extend this functionality to the nanoscale. Here, we report an approach to trap and detect nanoparticles and subwavelength cells at low optical power using a parallel photonic nanojet array produced by assembling microlenses on an optical fiber probe. Benefiting from the subwavelength confinement of the photonic nanojets, tens to hundreds of nanotraps were formed in three dimensions. Backscattering signals were detected in real time with single-nanoparticle resolution and enhancement factors of 10(3)-10(4). Selective trapping of nanoparticles and cells from a particle mixture or human blood solution was demonstrated using the nanojet array. The developed nanojet array is potentially a powerful tool for nanoparticle assembly, biosensing, single-cell analysis, and optical sorting.

Single Nanoparticle Detection Using Optical Microcavities

“…[148,163,164] Experiments have shown the detection of Raman emission of a 2 µm diameter PS particle on a fiber ring resonator, [165] and enhanced Raman scattering induced by single nanoparticles has been proposed by employing a high Q microcavity. [25][26][27][28][29]167] Although the detectable size (typically ≈10 2 nm) has not reached that of a microcavity, the nanofiber sensing technique is more economic, because it does not require an expensive tunable laser. [25][26][27][28][29]167] Although the detectable size (typically ≈10 2 nm) has not reached that of a microcavity, the nanofiber sensing technique is more economic, because it does not require an expensive tunable laser.…”

“…The monitoring of the nanoparticles in air is necessary for safety control, because nanoscale particles generated from vehicles and industrial processes can penetrate the lungs and spread to other organs, resulting in serious respiratory and cardiac diseases. While optical sensing with a detection limit down to single nanoparticles has been achieved by various methods, such as scattering interferometric [21,22] and photothermal microscopy [23,24] and nanofiber sensors, [25][26][27][28][29] microcavity sensing attracts much attention, because their high quality factors (Q factor) and small mode volumes (V m ) enable significant enhancement of light-matter interactions. Various methods designed for sensing applications, such as nanostructured materials, [4][5][6] metafilms, [7] carbon dots, [8,9] electrodes [10,11] and elastic nanocomposite cilia structures, [12] and wearable sensors have been reported.…”

“…[88] The field is centrally localized, and the cavity mode has a tail of evanescent part that fulfills the same role as a WGM cavity. 2017, 29,1604920 www.advancedsciencenews.com www.advmat.de Figure 1. In contrast to conventional PhCs, nanobeam cavities have one row of regular air holes with a slot (air-slot mode) or without a slot (air mode) between two adjacent cells, which can provide a relatively higher Q factor and smaller mode volume (Q ≈ 10 5 and V ≈ 0.01λ 3 /n air 3 , where n air is the refractive index of the air [90] ).…”

Overstepping the upper refractive index limit to form ultra-narrow photonic nanojets

“…Such a nonresonant, high-intensity light beam can propagate along a path extending beyond the evanescent field region without significant diffraction, and maintain a subwavelength full width at half-maximum (FWHM) transverse beamwidth. Over the past decade, many PNJ aspects have been extensively studied, such as backscattering enhancement 2 , Raman scattering 3 , PNJ induced optical force 4 , coupled resonator optical waveguide 5 , ultrahigh density optical data storage 6 , optical trap assisted nanopatterning 7 , super-resolution optical imaging 8 , ultrafast all-optical switching 9 , and manipulation and detection of nanoparticles and cells 10 . PNJ formation characteristics are determined by the considered microparticles’ material properties and geometrical morphologies, exterior environments, and illumination wavelength scales.…”

Silver Nanoprism-Loaded Eggshell Membrane: A Facile Platform for In Situ SERS Monitoring of Catalytic Reactions

“…Noble metal nanoparticles, including gold and silver nanoparticles, are currently of great interest for their distinctive plasmonic properties and extensive research attention in near-field related applications, such as surface-enhanced spectroscopy [1,2], biomedicine [3,4], photonics [5,6], and biosensing [7,8]. Recently, metal nanoparticle-based catalysis has become an increasing area of research [9,10].…”