title: Incidence of the core composition on the stability, the ROS production and the toxicity of CdSe quantum dots.
abstract: Mercaptosuccinic acid-capped CdSe and alloyed CdSe(S) QDs were prepared in aqueous solution at 100 and 170°C, respectively. These dots were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and UV-vis and photoluminescence spectroscopies. The dots were found to be of similar size (ca. 2nm) but differ in their composition and surface chemistry. The photostability of the QDs was found to correlate with their ability to produce reactive oxygen species (ROS) upon light activation. CdSe QDs produce hydroxyl radicals immediately after irradiation due to their modest photostability, while CdSe(S) QDs start to generate the hydroxyl radicals only once they start to be bleached (ca. 30min). Cytotoxicity experiments conducted on Escherichia coli cells revealed that CdSe QDs were the more toxic despite being the least loaded in cadmium. In addition, consistent with ROS assays, the cytotoxicity of the CdSe QDs appeared light-dependent and is in accordance with a light-dependent oxidative stress observed with an oxyR-based whole cell biosensor. Our results demonstrate the crucial role played by nanoparticles synthesis process on their PL properties, their stability and their toxicity.
authors: Université de Lorraine, Laboratoire Réactions et Génie des Procédés (LRGP), UMR 7274, CNRS, 1 rue Grandville, BP 20451, 54001 Nancy Cedex, France; Université de Lorraine, Laboratoire de Chimie Physique et Microbiologie pour l'Environnement (LCPME), UMR 7564, CNRS, 15 Avenue du Charmois, 54500 Vandoeuvre-lès-Nancy, France.
authors: Florence-Anaïs
authors: FA
authors: Kauffer
authors: Université de Lorraine, Laboratoire de Chimie Physique et Microbiologie pour l'Environnement (LCPME), UMR 7564, CNRS, 15 Avenue du Charmois, 54500 Vandoeuvre-lès-Nancy, France.
authors: Christophe
authors: C
authors: Merlin
authors: Institut de Science des Matériaux de Mulhouse (IS2M), LRC 7228, 15 rue Jean Starcky, 68093 Mulhouse, France.
authors: Lavinia
authors: L
authors: Balan
authors: Université de Lorraine, Laboratoire Réactions et Génie des Procédés (LRGP), UMR 7274, CNRS, 1 rue Grandville, BP 20451, 54001 Nancy Cedex, France. Electronic address: raphael.schneider@univ-lorraine.fr.
authors: Raphaël
authors: R
authors: Schneider
mesh_terms: D000497:Alloys; D019187:Cadmium Compounds / Q000138:chemical synthesis / Q000737:chemistry / Q000528:radiation effects / Q000633:toxicity*; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D018384:Oxidative Stress / Q000187:drug effects; D010316:Particle Size; D010777:Photochemistry; D045663:Quantum Dots; D017382:Reactive Oxygen Species / Q000737:chemistry*; D018036:Selenium Compounds / Q000138:chemical synthesis / Q000737:chemistry / Q000528:radiation effects / Q000633:toxicity*; D012995:Solubility; D013499:Surface Properties; D013870:Thiomalates / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D000497:Alloys; D019187:Cadmium Compounds; D017382:Reactive Oxygen Species; D018036:Selenium Compounds; D013870:Thiomalates; C046062:2-thiomalic acid; C058667:cadmium selenide
keywords: Aqueous synthesis; CdSe quantum dots; Cytotoxicity; Photostability; Reactive oxygen species