An international research team from the University of Texas-El Paso (UTEP) and Mexico advanced the work at the Stanford Synchrotron Radiation Laboratory (SSRL) - part of the Stanford Linear Accelerator Center (SLAC) in Menlo Park, Calif. The researchers are using, as tiny factories, the alfalfa's natural, physiological need to extract metals from the medium in which they are growing. Of most value here is that the alfalfa extracts gold from the medium and stores it in the form of nanoparticles - specks of gold less than a billionth of a meter across. Their findings are published in the April issue of Nano Letters, a publication of the American Chemical Society.
''This study is just one of hundreds of innovative research projects that take advantage of the unique properties of synchrotron X-rays provided by SSRL,'' said Keith Hodgson, the director of SSRL and a professor of chemistry at Stanford University.
The semiconductor industry has long valued the oxidation resistance and the thermal and electrical conductivity of gold. Now, the relentless and accelerating drive toward ever-smaller wires, connectors and through-holes on ever-smaller semiconductor devices makes those properties even more important to the folks who make very small things. Consequently, the nanotechnology industry is very interested in processes that make gold nanoparticles for nano-scale electronic and optical devices.
Some processes for making high concentrations of solid nanoparticles use chemistry. However, many of the chemical methods used are cumbersome and lead to poisonous end products that could endanger public health. A better method is needed. Ordinary plants, acting as tiny factories, may provide a better means of production.