Scientists Come Up with a New Technique for Coating Nanorods of Gold

Published Date : Mar 19, 2015

A team of researchers and scientists have developed a method for coating nanorods of gold with shells of silica thereby enabling engineers to develop huge amounts of nanorods and also ensure that they have greater control on the shell’s thickness. Researchers are investigating gold nanorods for using the same in different types of biomedical activities and applications. This advance is paving the path for greater quantity gold nanorods that are stable. This is also meant for functionalizing the shell surface chemically. 

There are several potential applications of gold nanorods since they possess surface Plasmon resonance, which means that they have the capacity to absorb and then scatter light. Also, via the dimension control of the gold nanorods, primarily with respect to the aspect ratio, one can control and manage the light’s wavelength that they absorb. These aforementioned features of gold nanorods, is what makes these highly attractive for applications in security materials, biomedical applications, cancer therapy, imaging, diagnostics, and catalysis. 

Gold nanorods are ideal for photothermal heating, which refers to the technique of converting the light that is absorbed into heat. However, if excessive amount of light is shone on the nanorods, it can lead to these losing their rod like shape and can become spherical, and thereby lose their ideal optical characteristics. A way of enabling gold nanorods retain the shape at the time of photothermal heating is by coating these with shells of silica. This ensures that the nanorods do not lose their shape and enable the entry of light through them. However, for several applications, it is vital to have a control over the thickness of the silica shells.