Quantum Dot Surfaces for Use In Vivo and In Vitro

Abstract

Publisher Summary This chapter reviews the recent advances in the use of quantum dots for biological imaging and the work done on the effects of chemically varying quantum dot surface properties to improve cellular uptake and imaging in vivo. Quantum dots—first introduced for biological labeling in 1998—have proved to be extraordinarily useful fluorescence reagents that have significant advantages over other types of fluorescent dyes. They combine very high brightness,because of high absorbency and high quantum yields, with unprecedented resistance to photo-bleaching. Emission wavelengths, governed primarily by composition and secondarily by size, range from near‐ultraviolet to infrared. The combination of high brightness, photo-stability, and narrow-emission bandwidths with the ability to excite many colors naturally leads to the possibility of using multicolor combinations of quantum dots to label or “bar‐code” large numbers of different objects. Quantum dots may be used for single‐molecule imaging in living cells. Quantum dots are well suited for two‐photon microscopy. There are potential drawbacks to the use of quantum dots: their large size and high molecular weights may limit applications that require measurement of molecular mobility, and attached quantum dots might interfere with molecular interactions. Since the current generation of quantum dots is composed of toxic heavy metals (CdSe and cadmium telluride [CdTe] cores, with ZnS shells), toxicity might be anticipated if the quantum dots degrade during use.