查看文章

Quantum dots (QDs) are semiconductor nanocrystals with size-dependent optical properties, which have great potential in many areas of application, such as solar cells, light-emitt ing devices, biological and medical imaging. 1 Of particular importance, they are considered as a new type of fluore scence probe for multicolor imaging due to their narrow emission spectra, high quantum yield and sin 이 e excitation light source requirement for multiple light emission. 2 There fore, preparation of well-dispersed and photochemicallystable QD nanocolloids in aqueous solution is prerequisite for many applications and numerous methods have been developed for this purpose. 2, 3 However, these surface modi fication processes often involve covalent bond formation between ligand and QD surface and cause significant changes in the physicochemical states ofthe QD surface atoms. As a result, dramatic degradation in the desired properties ofQDs were frequently observed, such as significant decreases in photochemical and/or colloidal stability, quantum yields (QY) and acceleration ofcoagulation/precipitation process. 4 To minimize these deteriorations in the desired properties of QDs, alternative methods have been developed. For instance, several QD surface modification methods based on hydrophobic interaction of surfactants, 5 synthetic block copolymers6 and phospholipid7 with capping molecules (eg, Trioctylphosphine oxide (TOPO)) of the QD surfaces were recently reported. In this short note, we will describe a simple but very effective method for the preparation of biocompatible QD nanocolloids in water, via nonspecific physical interaction …