The central goal of synthetic chemistry of colloidal nanocrystals at present is to discover functional materials. Such functional materials should help mankind to meet the tough challenges brought by the rapid depletion of natural resources and the significant increase of population with higher and higher living standards. With this thought in mind, this essay discusses the basic guidelines for developing this new branch of synthetic chemistry, including rational synthetic strategies, functional performance, and green chemistry principles.

High quality InAs/InP/ZnSe core/shell/shell quantum dots have been grown by a one-pot approach. This engineered quantum dots with unique near-infrared (NIR) fluorescence, possessing outstanding optical properties, and the biocompatibility desired for in vivo applications. The resulting quantum dots have significantly lower intrinsic toxicity compared to NIR emissive dots containing elements such as cadmium, mercury, or lead. Also, these newly developed ultrasmall non-Cd containing and NIR-emitting quantum dots showed significantly improved circulation half-life and minimal reticuloendothelial system (RES) uptake.

Formation of Mn²⁺-doped ZnSe quantum dots (Mn: ZnSe d-dots) with both branched and nearly spherical shapes has been studied. Structure analysis indicates that the Mn²⁺ dopants were localized in the core of a branched nanocrystal. The growth of branched d-dots, rather than spherical ones, was achieved by simply varying the concentration of two organic additives, fatty acids, and fatty amines. The photoluminescence properties of the branched nanocrystals were explored and compared with those of the nearly spherical particles.