Researchers have developed a method to create gold nanoparticles in water, according to a study conducted on April 19, 2018.
This discovery of creation of gold nanoparticles using water droplets was a surprise to the scientists of Stanford University, as they did not expect this result from the experiment. Richard Zare, study leader said that this technique is the latest discovery in the new field of on-droplet chemistry and this could lead to more environmentally friendly ways to produce nanoparticles of gold and other metals. He also said that the ability to carry out reactions in water will be a solution to the worry about contamination.
Gold is relatively unreactive in nature and is known as a noble metal. It is resistant to corrosion and oxidation, which is the reason for it to be the most popular metal for jewelry. Scientists, in mid-1980, had discovered that chemical aloofness of gold is only manifested at macroscopic scales. However, gold particles are chemically reactive and make excellent catalysts at nanometer scale. Gold nanostructures have found a wide range of applications in bio-imaging, drug delivery, toxic gas detection, and biosensors.
Until now, a combination of gold precursor chloroauric acid and a reducing agent such as sodium borohydride was the only reliable method to produce gold nanoparticles. During the reaction, electrons are transferred from the reducing agent to the chloroauric acid and gold atoms are liberated during the process. Based on the clumps formed by the gold atoms, nano-size beads, wires, rods, prisms and more can be formed.
Researchers observed that gold nanoparticle grew over 100,000 times faster in microdroplets. Jae Kyoo Lee, first author of the study said, “Much to our bewilderment, we found that gold nanostructures could be made without any added reducing agents.” The gold nanoparticles and nanowires were found to be fused together when viewed under the electron microscope. Furthermore, scaling up of this process could be a solution to eliminate the need for potentially toxic reducing agents that have harmful health side effects or that can pollute waterways.