Gold nanoparticles and quantum dots for bioimaging

Nanoparticles are the latest tool acquired by the science of bioimaging, serving primarily as new contrast agents, sensors, or signal enhancing agents in established and developing imaging techniques. This review focuses on the unique properties of two classes of nanoparticles: gold nanoparticles (GNP) and quantum dots, and how these properties are benefiting cellular and in vivo imaging. We discuss the surface plasmon resonance of GNP and its implications for various imaging techniques of biological relevance. Furthermore, the key properties of quantum dots are reviewed, and their use alone or in combination with traditional fluorescent dyes for biological imaging are described. The underlying principles of these techniques are provided, along with some representative examples.