Enhanced fluorescence imaging performance of hydrophobic colloidal ZnO nanoparticles by a facile method

A facile synthesis method for the formation of ZnO nanoparticles by using a double-phase reaction was demonstrated in this paper. The morphology of the synthesized ZnO nanoparticles shows a flower-shape. Hydrogen peroxide was used as a unique oxygenic source to promote the formation of ZnO in the presence of organic zinc precursor. The as-synthesized ZnO nanoparticles also show a stability and solubility in the aqueous environment. The structure and properties of ZnO nanoparticles were investigated by the transmission electron microscopy (TEM) and X-ray diffraction (XRD) as well as UV-vis and photoluminescence spectroscopy. The as-prepared hydrophobic colloidal ZnO nanoparticles could be modified to become water-soluble via ligand exchange with amineothanethiol center dot HCI while retaining the photoluminescence properties. In addition, the potential application for biological label of water-soluble ZnO nanopartides were also demonstrated. These results not only have applications towards using colloidal ZnO nanoparticles effectively in biological fluorescence imaging, but also promote its application in the field of targeted drug delivery. (C) 2014 Elsevier B.V. All rights reserved.