Navigation Links
Light touch keeps a grip on delicate nanoparticles
Date:5/4/2012

Using a refined technique for trapping and manipulating nanoparticles, researchers at the National Institute of Standards and Technology (NIST) have extended the trapped particles' useful life more than tenfold.* This new approach, which one researcher likens to "attracting moths," promises to give experimenters the trapping time they need to build nanoscale structures and may open the way to working with nanoparticles inside biological cells without damaging the cells with intense laser light.

Scientists routinely trap and move nanoparticles in a solution with "optical tweezers"a laser focused to a very small point. The tiny dot of laser light creates a strong electric field, or potential well, that attracts particles to the center of the beam. Although the particles are attracted into the field, the molecules of the fluid they are suspended in tend to push them out of the well. This effect only gets worse as particle size decreases because the laser's influence over a particle's movement gets weaker as the particle gets smaller. One can always turn up the power of the laser to generate a stronger electric field, but doing that can fry the nanoparticles too quickly to do anything meaningful with themif it can hold them at all.

NIST researchers' new approach uses a control and feedback system that nudges the nanoparticle only when needed, lowering the average intensity of the beam and increasing the lifetime of the nanoparticle while reducing its tendency to wander. According to Thomas LeBrun, they do this by turning off the laser when the nanoparticle reaches the center and by constantly tracking the particle and moving the tweezers as the particle moves.

"You can think of it like attracting moths in the dark with a flashlight," says LeBrun. "A moth is naturally attracted to the flashlight beam and will follow it even as the moth flutters around apparently at random. We follow the fluttering particle with our flashlight beam as the particle is pushed around by the neighboring molecules in the fluid. We make the light brighter when it gets too far off course, and we turn the light off when it is where we want it to be. This lets us maximize the time that the nanoparticle is under our control while minimizing the time that the beam is on, increasing the particle's lifetime in the trap."

Using this method at constant average beam power, 100-nanometer gold particles remained trapped 26 times longer than had been seen in previous experiments. Silica particles 350 nanometers in diameter lasted 22 times longer, but with the average beam power reduced by 33 percent. LeBrun says that their approach should be able to be combined with other techniques to trap and hold even smaller nanoparticles for extended periods without damaging them.

"We're more than an order of magnitude ahead of where we were before," says LeBrun. "We now hope to begin building complex nanoscale devices and testing nanoparticles as sensors and drugs in living cells."


'/>"/>

Contact: Mark Esser
mark.esser@nist.gov
301-975-8735
National Institute of Standards and Technology (NIST)
Source:Eurekalert  

Related biology technology :

1. Corporate Venturing and Early-Stage Financing in the Spotlight at BioTrinity
2. CMC Biologics Highlights Technical Acumen at Upcoming Conferences
3. Handheld plasma flashlight rids skin of notorious pathogens
4. UCSB Physicists mix 2 lasers to create light at many frequencies
5. Soligenix Reports Year-End 2011 Financial Results and Highlights Recent Accomplishments
6. Proteins shine a brighter light on cellular processes
7. Designer lights from the physics lab
8. Nano spiral staircases modify light
9. FasterCures Spotlights Addario Lung Cancer Medical Institutes Innovative Research Programs
10. Valkee and University of Oulu Publish the First Clinical Trial on Bright Light Therapy Channeled via ear Canals in Seasonal Depression
11. Stanford engineers weld nanowires with light
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Light touch keeps a grip on delicate nanoparticles
(Date:2/20/2017)... , ... February 20, 2017 , ... ... the re-launch of “Crosswalk Insight: Oncology™” (Crosswalk), a unique precision medicine knowledge visualization ... can now be accessed through Inspirata’s diagnostic cockpit and is downloadable as an ...
(Date:2/20/2017)... ... February 20, 2017 , ... PuraCath ... associated with peritoneal dialysis, announced today that it has published the result of ... in Peritoneal Dialysis International (PDI), the official Journal of the International Society ...
(Date:2/20/2017)...  Atrius Health and IBM (NYSE: IBM ... to develop a cloud based service designed to ... view of the multiple influences on an individual,s ... be designed to support shared decision making between ... nonprofit healthcare organization with 875 physicians caring for ...
(Date:2/18/2017)... ... February 17, 2017 , ... The BMT ... the Center for International Blood & Marrow Transplant Research (CIBMTR) will take place ... , The combined scientific sessions offer investigators, clinicians, laboratory technicians, clinical research ...
Breaking Biology Technology:
(Date:2/14/2017)... WINSTON-SALEM, N.C. , Feb. 14, 2017  Wake ... FRY-shlog), M.D., as its new chief executive officer (CEO). ... succeeds CEO John D. McConnell , M.D., who ... new position at the Medical Center, after leading it ... oversee the full scope of Wake Forest Baptist,s academic ...
(Date:2/10/2017)... -- Research and Markets has announced the ... Scientific and Commercial Aspects" to their offering. ... Biomarkers play ... therapy for selection of treatment as well for monitoring the ... disease in modern medicine. Biochip/microarray technologies and next generation sequencing ...
(Date:2/8/2017)... (NASDAQ: AWRE ), a leading supplier of biometrics ... and year ended December 31, 2016. Revenue ... to $6.9 million in the same quarter last year. Operating ... compared to $2.6 million in the fourth quarter of 2015. ... million, or $0.02 per diluted share, which compares to $1.8 ...
Breaking Biology News(10 mins):