Biocompatible Water Soluble UV-Blue Emitting ZnSe Quantum Dots for Biomedical Applications

ZnSe quantum dots are wide-band gap materials suitable for UV-blue-emitting applications like laser diode or biolabeling probes. Initially, an organometallic approach have been proposed for preparing these quantum dots with high quantum yield (QY), crystallinity and monodispersity. Although, the chemicals used in this procedures are toxic, expensive, pyrophoric and even explosive. Aiming to develop a more convenient and applicable methodology we propose an alternative methods to synthesize blue-emitting ZnSe/ZnS nanocrystals in aqueous media. This work presents a new methodology using chemometric analysis for improving the quantum yield of these blue probes under aqueous colloidal synthesis. The structural characterization performed by X-Ray diffraction and transmission electronic microscopy shows that this material is in the strong confinement regime with average diameter of 2.5 nm with zinc blend crystalline structure. The optical properties of the colloids demonstrate a large Stoke's shift between the absorption band (360 nm) and the emission peak (420 nm) with a half maximum at full width of 30 nm and a maximum quantum yield of 43%.