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Tiny tweezer developed at Vanderbilt can trap molecules on a nanoscale, creating powerful research capabilities into cancer metastasis, neurodegenerative diseases

Posted by on Tuesday, September 1, 2020 in News.

In 2018, one-half of the Nobel Prize was awarded to Arthur Ashkin, the physicist who developed optical tweezers, the use of a tightly focused laser beam to isolate and move micron-scale objects (the size of red blood cells). Now Justus Ndukaife, assistant professor of electrical engineering at Vanderbilt University, has developed the first-ever opto-thermo-electrohydrodynamic tweezers, optical nanotweezers that can trap and manipulate objects on an even smaller scale.

The article, “Stand-off trapping and manipulation of sub-10 nm objects and biomolecules using opto-thermo-electrohydrodynamic tweezers” was published online in the journal Nature Nanotechnology on August 31.

The article was authored by Ndukaife and graduate students Chuchuan Hong and Sen Yang, who are conducting research in Ndukaife’s lab.

Justus Ndukaife
Justus Ndukaife (Vanderbilt Magazine)

Micron-scale optical tweezers represent a significant advancement in biological research but are limited in the size of the objects they can work with. This is because the laser beam that acts as the pincer of an optical tweezer can only focus the laser light to a certain diameter (about half the laser’s wavelength). In the case of red light with a wavelength of 700 nanometers, the tweezer can focus on and manipulate only objects with a diameter of approximately 350 nanometers or greater using low power. Of course, size is relative, so while a size of 350 nanometers is extremely small, it leaves out the even smaller molecules such as viruses, which come in at 100 nanometers, or DNA and proteins that measure less than 10 nanometers.

The technique that Ndukaife established with OTET leaves several microns between the laser beam and the molecule it is trapping, another important element of how these new, tiny tweezers work. “We have developed a strategy that enables us to tweeze extremely small objects without exposing them to high-intensity light or heat that can damage a molecule’s function,” Ndukaife said. “The ability to trap and manipulate such small objects gives us the ability to understand the way our DNA and other biological molecules behave in great detail, on a singular level.”

Full article here.

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