New Nanoparticle Steals Light, Beams It Stronger
The particle could improve several existing technologies that use dyes, biomarkers or fluorescent tracers.
Physicists have developed a new kind of ceramic nanoparticle that they say will make it easier to track drugs in the body, screen counterfeit money and boost the ability of solar cells to capture more energy.
The onion-like particle is only 50 nanometers wide, which is about 1,000 times smaller than a human hair, or the size of a virus. It is made from layers of unusual materials: a coating of organic dye, a neodymium shell and a core made of ytterbium and thulium. Together, the layers convert invisible near-infrared light to blue and ultraviolet (UV) light with high efficiency.
The ability to convert one kind of light to another is called "up-conversion" and this particle is able to do it 100 time more efficiently than other particles.
It's important because such a particle could improve several existing technologies that use dyes, biomarkers or fluorescent tracers.
For example, the particles could be used in special inks that would be invisible to the naked eye, but glow blue when hit by a low-energy laser pulse - something almost impossible for counterfeiters to reproduce, said Tymish Y. Ohulchanskyy, deputy director University at Buffalo's Institute for Lasers, Photonics, and Biophotonics.
Ohulchanskyy said the particles could also be used to make sure that expensive drugs reach their target in the body. Currently this is done using "bio-imaging," a technique that tags cells with markers that fluoresce under ultraviolet light shined from specialized imagers.
But fluorescent markers can scatter the incoming light from the imaging device. The new nanoparticle doesn't. Rather it creates it's own "glow" during the up-conversion process.
"This is a feature that none of the other materials display," Ohulchanskyy said.
Researchers say the particle's dye acts as an antenna, gathering photons from low-energy light sources. The shell of neodymium transfers the energy to the core, where the ytterbium and thulium amass the energy of several photons at once and then emits it as a single photon of blue and UV light.
With this ability to capture and boost photons to a higher energy state, the nanoparticle could also be used to capture energy from solar panels and convert it to higher level of electric current, the team says.
Zhihong Nie, professor of chemistry at the University of Maryland and an expert in nanoparticles said he was impressed with the new three-layer particle.
"It's an outstanding paper in general," Nie said. "It's interesting to look at the energy cascade phenomena and it shouldn't be hard to replicate. I believe they should be able to scale it up."
The research was published in the journal "NanoLetters" and led by researchers at SUNY-Buffalo, the Harbin Institute of Technology in China, with contributions from the Royal Institute of Technology in Sweden; Tomsk State University in Russia; and the University of Massachusetts Medical School.
The particle's shell of neodymium transfers low-energy photons to the core, where materials amass the energy of several photons at once and then emits it as a single photon of blue and UV light.
Sept. 27, 2011 --
In the popular "Deus Ex" video game series, nanotechnology can turn an average government agent into a bionic superman. In fact, nanotech augmentations in the human body aren't just fun and games. Real-life applications will most likely become reality a lot sooner than you think. In 2007, the world's first online inventory of nanotech products, Project on Emerging Nanotechnologies, found that nearly 500 products, including food, clothing and cosmetics, employed nanotechnology. In this slide show, explore how nanotech can make you stronger, tap into your brain and more.
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If you're too busy to make it to the gym, nanotechnology could be a way to get fit without having to spend hours toiling away on machines. In fact, technology can take you a lot further than any free-weight or cardio regimen. In 2006, researchers at the University of Texas at Dallas reported in the journal Science that they had created alcohol- and hydrogen-fueled artificial muscles 100 times stronger and capable of 100 times more work than natural muscles. Functioning as both muscles and fuel cells, the technology has a range of applications from artificial limbs to autonomous robots.
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If nanotechnology can make you stronger, could it also make you smarter? Scientists aren't quite there yet, but nanotechnology applied to brain implants could treat a range of conditions from deafness to blindness to Parkinson's disease and more, according to biomedical engineers from the University of Michigan. Nanotechnology could also be used to tap into the mind, and read and write information directly into the brain. In an unusual twist, the research was undertaken by telecommunications engineers at Nippon Telegraph and Telephone.
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Tired of having to find an electrical outlet or a USB cable every time you need to charge your cell phone? With nanotechnology, you can become a walking battery. Using nanowires to recover wasted heat energy from the body, which is then converted into electrical power, researchers with the U.S. Department of Energy’s Lawrence Berkeley National Laboratory and the University of California at Berkeley have developed an entirely means of charging personal electronics. The same technology could be used to convert heat from other sources into electrical energy. As reported in the journal Nature, approximately 15 trillion watts of heat energy produced by engine and steam- and gas-powered turbines is lost to the environment.
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