 Gold nanoparticles have been used extensively in the field of nanomedicine due to their unique optical properties. These particles are able to absorb light energy and convert it into heat, making them ideal for use in photothermal therapies. They can also be used for cancer imaging and spectroscopy, as they have strong absorption capabilities and can be shaped or structured to target specific areas. This article was authored by Xiaohua Huang and Mustafa A.L. Syed.