Researchers are developing plasmonic nanotweezers to catch cancerous nanoparticles more quickly
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Illustration and theoretical analysis of the GET system. Illustration of how the GET system operates. A tangential AC field induces an outward diagonal electro-osmotic flow. By harnessing a circular geometry with a void zone, the electro-osmotic flow oscillating outwards diagonally creates a stagnant zone in the center of the void zone where trapping occurs. b The square-mesh nano-array generates an outward reciprocating osmotic electrical flow. c Four square grid arrays create alternating electro-osmotic flows that converge to the center. d A radial grating nano-array generates alternating electro-osmotic fluxes that converge to the center of the void region. b–d shows the evolution from a square-lattice nanoarray to a radial-lattice nanoarray. e The radiative energy flux of a dipole fluorescence emitter placed in the center of the void region demonstrating the ability to harness the GET trap to also irradiate the photons emitted by the trapped particles. f COMSOL simulation of the radial electroosmotic flow showing that the geometry of the void region leads to an opposite electroosmotic flow that forms a stagnation region at the center. Particle trapping occurs in the center of the void region where the flux vectors converge. The particle compensation position is marked with green dots, the g SEM image of the array of plasmonic surfaces with empty regions, and a magnified version of the individual GET trap. Each empty region represents a GET trap and can be easily scaled from hundreds to thousands or millions as desired. credit: Nature Communications (2023). doi: 10.1038/s41467-023-40549-7
Researchers from Vanderbilt University have developed a way to more quickly and accurately trap nanoscale objects, such as potentially cancerous extracellular vesicles, using advanced plasmonic nanotweezers.
This practice was done by Justus Ndukaife, assistant professor of electrical engineering, and Chuchuan Hong, a recent Ph.D. student of the Ndukaife Research Group, and currently a Postdoctoral Research Fellow at Northwestern University, published in Nature Communications.
Optical tweezers, which won the 2018 Nobel Prize in Physics, have proven adept at working with micron-sized materials such as biological cells. But their effectiveness is diminished when dealing with nanoparticles. This limitation arises from a light diffraction limit that prevents light from being focused at the nanoscale.
A new concept in nanoscience, called plasmonics, is being used to push past the diffraction limit and confine light to the nanoscale. However, trapping the nanoparticles near the plasmonic structures can be a lengthy process due to waiting for the nanoparticles to randomly approach the structures.
But Ndokaife and Hong provided a faster solution by introducing a high-throughput plasmonic nanotweezers technology called “engineered induced electrohydrodynamic tweezers” (GET), which enables the rapid, parallel capture and localization of individual nanoscale biological objects such as extracellular vesicles near plasmonic cavities within seconds without No harmful heating effects.
“This achievement represents an important scientific breakthrough and ushers in a new era for optical trapping at the nanoscale using plasmons,” says Ndukayeve. “This technique can be used to capture and analyze single extracellular vesicles in high-throughput to understand their essential roles in diseases such as cancer.”
Ndukaife recently published a research paper Nano Letters which discusses the use of photonic annelids to more effectively trap vesicles and extracellular nanoparticles for analysis of their roles in cancer and neurodegenerative diseases.
more information:
Zhouchuan Hong et al., Scalable Trapping of Single, Nanoscale Extracellular Vesicles Using Plasmons, Nature Communications (2023). doi: 10.1038/s41467-023-40549-7
Journal information:
Nature Communications
Nano letters
