title: Stability and toxicity of ZnO quantum dots: interplay between nanoparticles and bacteria.
abstract: The toxicity of quantum dots (QDs) has been commonly attributed to the release of metal ions from the core as well as to the production of reactive oxygen species. However, the information related to the stability of the nanoparticles are relatively scarce although this parameter may strongly influence their toxicity. The stability of aminosilane-capped ZnO QDs, here used as model nanoparticles, was investigated by inductively coupled plasma-optical emission spectrometer (ICP-OES) and whole cell biosensors using a dialysis setup to separate the QDs from the leaked Zn(2+) ions. The integrity of the ZnO QDs appeared strongly affected by their dilution in aqueous medium, whereas the nanoparticles were slightly stabilized by bacteria. Our results demonstrate some inadequacy between the implementation and use of whole cell biosensors, and the monitoring of metal release from QDs.
authors.affiliation: Université de Lorraine and CNRS, Laboratoire de Chimie Physique et Microbiologie pour l'Environnement (LCPME), UMR 7564, 15 Avenue du Charmois, 54500 Vandœuvre-lès-Nancy, France. Electronic address: xavier.bellanger@univ-lorraine.fr.
authors.forename: Xavier
authors.initials: X
authors.lastname: Bellanger
authors.affiliation: Université de Lorraine and CNRS, Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), UMR 7360, Boulevard des Aiguillettes, Faculté des Sciences et Techniques, BP 70239, 54506 Vandœuvre-lès-Nancy, France. Electronic address: patrick.billard@univ-lorraine.fr.
authors.forename: Patrick
authors.initials: P
authors.lastname: Billard
authors.affiliation: Université de Lorraine and CNRS, Laboratoire Réactions et Génie des Procédés (LRGP), UMR 7274, 1 rue Grandville, BP 20451, 54001 Nancy Cedex, France. Electronic address: raphael.schneider@univ-lorraine.fr.
authors.forename: Raphaël
authors.initials: R
authors.lastname: Schneider
authors.affiliation: Institut de Science des Matériaux de Mulhouse (IS2M), UMR 7361, CNRS, 15 rue Jean Starcky, 68093 Mulhouse, France. Electronic address: lavinia.balan@uha.fr.
authors.forename: Lavinia
authors.initials: L
authors.lastname: Balan
authors.affiliation: Université de Lorraine and CNRS, Laboratoire de Chimie Physique et Microbiologie pour l'Environnement (LCPME), UMR 7564, 15 Avenue du Charmois, 54500 Vandœuvre-lès-Nancy, France. Electronic address: christophe.merlin@univ-lorraine.fr.
authors.forename: Christophe
authors.initials: C
authors.lastname: Merlin
mesh_terms: D001419:Bacteria / Q000187:drug effects / Q000378:metabolism; D015374:Biosensing Techniques; D015386:Hazardous Substances / Q000633:toxicity*; D045663:Quantum Dots / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism; D015034:Zinc Oxide / Q000633:toxicity*
chemical_list: D015386:Hazardous Substances; D017382:Reactive Oxygen Species; D015034:Zinc Oxide
keywords: Cupriavidus metallidurans; Escherichia coli; QDs toxicity; Zn(2+)bioavailability; ZnO QDs stability