In the future, industrial nanoparticles may not be produced in a laboratory, but grown in fields of genetically engineered crops - what might be called “particle farming.” It’s been known for some time that plants can use their roots to extract nutrients and minerals from the soil but research from the University of Texas-El Paso confirms that plants can also soak up nanoparticles that could be industrially harvested. In one particle farming experiment, alfalfa plants were grown on an artificially gold-rich soil on university grounds. When researchers examined the plants, they found gold nanoparticles in the roots and along the entire shoot of the plants that had physical properties like those produced using conventional chemistry techniques, which are expensive and harmful to the environment. The metals are extracted simply by dissolving the organic material.
Research Suggests that Particle Plants Are Best Grown in Gold-Rich Soil
Initial experiments showed that the gold particles formed in random shapes, but changing the acidity of the growing medium appears to result in more uniform shapes. The researchers are now working with other metals and with wheat and oats in addition to alfalfa to produce nanoparticles of silver, Europium, palladium, platinum and iron. For industrial-scale production, the researchers speculate that the particle plants can be grown indoors in gold-enriched soils, or they can be farmed nearby abandoned gold mines.
Other Research Projects into Particle Farming and Particle Plants
Meanwhile, nanobiotech researchers at the National Chemistry Laboratory in Pune, India, have been carrying out similar work with geranium leaves immersed in a gold-rich solution. After 3-4 hours, the leaves produce 10 nm-sized particles shaped as rods, spheres and pyramids which, according to researcher Murali Sastry, appear to be shaped according to the aromatic compounds in the leaves. By altering those aromatic compounds, Sastry believes it will be possible to alter the shape of the nanoparticles (and their properties).