title: A facile method for the preparation of bifunctional Mn:ZnS/ZnS/Fe3O4 magnetic and fluorescent nanocrystals.
abstract: Bifunctional magnetic and fluorescent core/shell/shell Mn:ZnS/ZnS/Fe3O4 nanocrystals were synthesized in a basic aqueous solution using 3-mercaptopropionic acid (MPA) as a capping ligand. The structural and optical properties of the heterostructures were characterized by X-ray diffraction (XRD), dynamic light scattering (DLS), transmission electron microscopy (TEM), UV-vis spectroscopy and photoluminescence (PL) spectroscopy. The PL spectra of Mn:ZnS/ZnS/Fe3O4 quantum dots (QDs) showed marked visible emission around 584 nm related to the (4)T1 → (6)A1 Mn(2+) transition. The PL quantum yield (QY) and the remnant magnetization can be regulated by varying the thickness of the magnetic shell. The results showed that an increase in the thickness of the Fe3O4 magnetite layer around the Mn:ZnS/ZnS core reduced the PL QY but improved the magnetic properties of the composites. Nevertheless, a good compromise was achieved in order to maintain the dual modality of the nanocrystals, which may be promising candidates for various biological applications.
authors.affiliation: Unité de Recherche Synthèse et Structure de Nanomatériaux UR 11 ES 30, Université de Carthage, Faculté des Sciences de Bizerte, 7021 Jarzouna, Bizerte, Tunisia.
authors.forename: Houcine
authors.initials: H
authors.lastname: Labiadh
authors.affiliation: Unité de Recherche Synthèse et Structure de Nanomatériaux UR 11 ES 30, Université de Carthage, Faculté des Sciences de Bizerte, 7021 Jarzouna, Bizerte, Tunisia.
authors.forename: Tahar
authors.initials: T
authors.lastname: Ben Chaabane
authors.affiliation: Institut Jean Lamour (IJL), Université de Lorraine, CNRS, UMR 7198, CNRS, BP 70239, 54506 Vandoeuvre-lès-Nancy Cedex, France.
authors.forename: Romain
authors.initials: R
authors.lastname: Sibille
authors.affiliation: Institut de Science des Matériaux de Mulhouse (IS2M), CNRS, UMR 7361, 15 rue Jean Starcky, 68093 Mulhouse, France.
authors.forename: Lavinia
authors.initials: L
authors.lastname: Balan
authors.affiliation: Université de Lorraine, Laboratoire Réactions et Génie des Procédés (LRGP), UMR 7274, CNRS, 1 rue Grandville, BP 20451, 54001 Nancy Cedex, France.
authors.forename: Raphaël
authors.initials: R
authors.lastname: Schneider
keywords: Mn-doped ZnS; aqueous synthesis; bifunctional nanocrystals; magnetite; quantum dots