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:6/23/2016)... ... 23, 2016 , ... Supplyframe, the Industry Network for electronics ... Lab . Located in Pasadena, Calif., the Design Lab’s mission is to bring ... designed, built and brought to market. , The Design Lab is Supplyframe’s physical ...
(Date:6/23/2016)... 23, 2016 Apellis Pharmaceuticals, Inc. today ... trials of its complement C3 inhibitor, APL-2. The ... ascending dose studies designed to assess the safety, ... injection in healthy adult volunteers. Forty ... a single dose (ranging from 45 to 1,440mg) ...
(Date:6/23/2016)... NEW YORK , June 23, 2016 ... the trading session at 4,833.32, down 0.22%; the Dow Jones ... the S&P 500 closed at 2,085.45, down 0.17%. Stock-Callers.com has ... INFI ), Nektar Therapeutics (NASDAQ: NKTR ... BIND Therapeutics Inc. (NASDAQ: BIND ). Learn more ...
(Date:6/23/2016)... ... 23, 2016 , ... Velocity Products, a division of Morris ... optimized exclusively for Okuma CNC machining centers at The International Manufacturing Technology Show, ... several companies with expertise in toolholding, cutting tools, machining dynamics and distribution, Velocity ...
Breaking Biology Technology:
(Date:6/9/2016)... Paris Police Prefecture ... solution to ensure the safety of people and operations in ... major tournament Teleste, an international technology group specialised ... today that its video security solution will be utilised by ... public safety across the country. The system roll-out is scheduled ...
(Date:6/3/2016)... , June 3, 2016 ... von Nepal hat ... Lieferung hochsicherer geprägter Kennzeichen, einschließlich Personalisierung, Registrierung ... in der Produktion und Implementierung von Identitätsmanagementlösungen. ... Ausschreibung im Januar teilgenommen, aber Decatur wurde ...
(Date:6/2/2016)...   The Weather Company , an IBM Business (NYSE: ... capability in which consumers will be able to interact with ... via voice or text and receive relevant information about the ... Marketers have long sought an advertising solution that can create ... relevant and valuable; and can scale across millions of interactions ...
Breaking Biology News(10 mins):