Plasmon Resonances in Biology and Medicine
Jason Hafner, Rice University
Noble metal nanoparticles that range from only a few nanometers to hundreds of nanometers in diameter exhibit an optical property called localized surface plasmon resonance. This effect, which is essentially a classical resonance of the nanoparticle’s electrons when driven by light, has been known and understood for over one hundred years. However, the past decade has seen intense interest in the phenomenon due to new abilities to control nanoparticle shape, new methods to study the effect, and the potential impact of the effect on many fields. For example, the plasmonic optical properties of gold nanoparticles create unique opportunities in biological and biomedical research. Their strong, tunable scattering at visible wavelengths leads to microscopic imaging labels, their sensitivity to the molecular environment yields label-free biological assays, and their enhanced optical absorption enables novel cancer therapies and drug delivery strategies. To achieve the full impact of these applications, fundamental questions regarding the nanoparticle optical properties and interfacial chemistry must be addressed. Here I will describe how nanoparticle size and shape can be manipulated through their chemical synthesis, and how those properties affect the plasmon resonances, as well as nanoparticle interactions with their molecular environment.