title: Layer-by-layer assembled Fe3O4@C@CdTe core/shell microspheres as separable luminescent probe for sensitive sensing of Cu2+ ions.
abstract: A novel multifunctional microsphere with a fluorescent CdTe quantum dots (QDs) shell and a magnetic core (Fe(3)O(4)) has been successfully developed and prepared by a combination of the hydrothermal method and layer-by-layer (LBL) self-assembly technique. The resulting fluorescent Fe(3)O(4)@C@CdTe core/shell microspheres are utilized as a chemosensor for ultrasensitive Cu(2+) ion detection. The fluorescence of the obtained chemosensor could be quenched effectively by Cu(2+) ions. The quenching mechanism was studied and the results showed the existence of both static and dynamic quenching processes. However, static quenching is the more prominent of the two. The modified Stern-Volmer equation showed a good linear response (R(2) = 0.9957) in the range 1-10 μM with a quenching constant (K(sv)) of 4.9 × 10(4) M(-1). Most importantly, magnetic measurements showed that the Fe(3)O(4)@C@CdTe core/shell microspheres were superparamagnetic and they could be separated and collected easily using a commercial magnet in 10 s. These results obtained not only provide a way to solve the embarrassments in practical sensing applications of QDs, but also enable the fabrication of other multifunctional nanostructure-based hybrid nanomaterials.
authors.affiliation: Department of Chemistry, Jilin University, Changchun, 130021, People's Republic of China.
authors.forename: Hengguo
authors.initials: H
authors.lastname: Wang
authors.forename: Lei
authors.initials: L
authors.lastname: Sun
authors.forename: Yapeng
authors.initials: Y
authors.lastname: Li
authors.forename: Xiaoliang
authors.initials: X
authors.lastname: Fei
authors.forename: Mingda
authors.initials: M
authors.lastname: Sun
authors.forename: Chaoqun
authors.initials: C
authors.lastname: Zhang
authors.forename: Yaoxian
authors.initials: Y
authors.lastname: Li
authors.forename: Qingbiao
authors.initials: Q
authors.lastname: Yang
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry* / Q000302:isolation & purification; D002244:Carbon / Q000737:chemistry* / Q000302:isolation & purification; D002623:Chemistry Techniques, Analytical / Q000295:instrumentation*; D003300:Copper / Q000032:analysis*; D052203:Ferrosoferric Oxide / Q000737:chemistry* / Q000302:isolation & purification; D049408:Luminescent Agents / Q000737:chemistry / Q000302:isolation & purification; D008163:Luminescent Measurements; D008863:Microspheres; D055616:Microtechnology / Q000379:methods*; D013691:Tellurium / Q000737:chemistry* / Q000302:isolation & purification; D014867:Water / Q000737:chemistry
chemical_list: D019187:Cadmium Compounds; D049408:Luminescent Agents; D014867:Water; D002244:Carbon; D003300:Copper; D013691:Tellurium; C028337:cadmium telluride; D052203:Ferrosoferric Oxide