Quantum dot
Quantum dots are inorganic nanocrystal semiconductors that behave exceptionally well as fluorophores. In the field of biology, fluorophores are one of the few tools that allow us to peer inside of a live biological system at a cellular level. As a fluorophore, the size of a quantum dot directly reflects the wavelength of light emitted, allowing for a highly tunable color spectrum. Since the size of quantum dots are controllable and an increased size produces an increased wavelength range of emission, researchers are able to paint pictures on the cellular and sub-cellular levels with this technology. The current problem with common CdSe-ZnS quantum dots is that Cd is toxic to cells To prevent this problem researches are developing ways to modify the quantum dot surfaces for biocompatibility, in addition to the development of Cd-free quantum dots (“CFQDs”). After a surface modification has been made to limit toxicity, the particle can be further coated with a hydrogel or bioconjugate layer to selectively bind to DNA, which may then be used for cellular or molecular level detection.