Carboxymethylcellulose/ZnCdS fluorescent quantum dot nanoconjugates for cancer cell bioimaging

In this study, it is reported the use of sodium carboxymethyl cellulose (CMCel) as a multifunctional biocompatible polysaccharide for the direct synthesis of fluorescent alloyed-ZnCdS quantum dot (QD) nanoconjugates via aqueous 'green" process at room temperature. The nanoconjugates were extensively characterized by spectroscopical (NMR, FFIR, UV-vis, PL) and morphological techniques (DLS, TEM) for accessing their structural and physicochemical properties associated with X-ray photoelectron spectroscopy (XPS) for surface and interface analysis. The results proved the hypothesis of formation of core-shell nanostructures composed by the semiconductor ZnCdS QD core and the organic biocompatible ligand CMCeI shell. Moreover, CMCeI chemical functional groups played a pivotal role for controlling the size of water-soluble colloidal nanocrystals (2r = 4-5 nm) and hydrodynamic diameters (<15 nm) evidenced by metal complexation and interactions at the nanointerfaces. Additionally, these nanoconjugates were cytocompatible and luminescent for bioimaging human osteosarcoma cancer cells. Thus, these novel polysaccharide-based fluorescent bioconjugates offer promising perspectives as nanoplatforms for cancer cell bioimaging and diagnosis purposes. (C) 2016 Elsevier B.V. All rights reserved.