Synthesis and characterization of blue emitting ZnSe quantum dots

In this work we show a new experimental methodology to obtain ZnSe nanocrystals in aqueous solution aiming their application as biophotonic probes. The nanocrystals were obtained using a simple procedure based on the arrested precipitation of ZnSe in aqueous solution in the presence of a thiol-alkyl stabilizing agent, in air and at room temperature. Using post-preparative experimental procedures on the colloidal particles, blue and green emissions were observed. The structural characterization (powder X-ray diffraction and electronic transmission microscopy) shows that the particles were obtained in the quantum confinement regime (d = 2-4 nm) and possess a zinc-blend crystalline structure. The optical properties of the suspensions were determined by electronic absorption, excitation and emission spectroscopies and are discussed in terms of their size and chemical compositions. (C) 2008 Elsevier Ltd. All rights reserved.