ABSTRACT
This chapter discusses relevant issues regarding the biological application of semiconductor quantum dots, either as diagnostic or as therapeutic tools. It focuses on the properties, preparation, and surface modification of the nanocrystals and their usage as fluorescence probes for in vitro and in vivo imaging, in Forster resonance energy transfer bioanalysis, DNA sensing, and photodynamic therapy. The chapter also examines the toxicity concerns associated with their use. In diagnostics and therapeutics, QDs have been investigated as advantageous substitutes for organic fluorophore or fluorescent protein in vivo or in vitro imaging and targeting, as active scaffolds in drug delivery, and in photodynamic therapy. The applicability of QDs arises from a multiplicity of attributes, including easily tailored surface chemistry and similarity of size with biomolecules, such as polynucleic acids, proteins, antibodies and antigens, which offer an platform for the establishment of selected interactions with the target species.
