Structural, optical and crystal field analyses of undoped and Mn2+-doped ZnS nanoparticles synthesized via reverse micelle route

Whiffen, Radenka Krsmanović; Jovanović, Dragana J.; Antić, Željka; Bártová, Barbora; Milivojević, D.; Dramićanin, Miroslav D.; Brik, M.G.

doi:10.1016/j.jlumin.2013.09.032

Cited by 63 publications

(25 citation statements)

References 44 publications

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“…Unsurprisingly, the total concentration of incorporated isolated Mn 2+ ions is much lower than the nominal concentration, in agreement with the low doping efficiency observed in Mn doped II-VI nanostructures. 6,7,[28][29][30][31] For the samples with nominal concentrations lower than 100 ppm the low incorporation efficiency resulted in very low intensity X-band spectra, and, therefore, in unreliable quantitation results.…”

Section: Epr Resultsmentioning

confidence: 99%

On the agent role of Mn²⁺ in redirecting the synthesis of Zn(OH)₂ towards nano-ZnO with variable morphology

et al. 2016

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One of the simplest routes to prepare polycrystalline Zn(OH) 2 is by coprecipitation, with zinc nitrate as a cation source. However, the addition of even minute amounts of manganese nitrate to the precursors used to prepare pure Zn(OH) 2 results in Mn 2+ doped nanostructured ZnO. The comparison with other Mn 2+ doped metal hydroxides prepared by the same coprecipitation method, involving metal nitrates precursors, shows that this behavior is unique, pertaining only to Zn(OH) 2 . A systematic study of the samples prepared without and with variable amounts of Mn 2+ ions, in the 1 to 5000 ppm nominal concentrations range showed that the re-routing of the reaction takes place even for the lowest nominal dopant concentration of 1 ppm. According to X-ray diffraction, transmission electron microscopy and Fourier transform infrared spectroscopy investigations, both crystallite size and morphology of the resulting nanostructured ZnO samples varied with the Mn 2+ nominal concentration. Moreover, quantitative electron paramagnetic resonance investigations showed that the incorporation rate of the Mn 2+ ions at different sites in the nanostructured ZnO depended on the nominal Mn 2+ concentration. The results are discussed in terms of the coordination properties of the Mn 2+ and Zn 2+ ions and the nature of the reaction precursors.Fig. 2 TEM/HRTEM images and the corresponding ED patterns (insets) for the ZnO samples doped with 1 ppm (a), 1000 ppm (b), 5000 ppm (c) Mn 2+ nominal concentration. (d) HRTEM image at larger magnification of the sample with Mn 2+ 5000 ppm nominal concentration. The ED patterns were indexed with the ZnO structure. 106734 | RSC Adv., 2016, 6, 106732-106741 This journal isFig. 3 Multiscan Q-band EPR spectra for the undoped (bottom) and Mn 2+ doped (upper) samples. The six hyperfine lines/doublet-lines of the Mn 2+ (a), Mn 2+ (d)/Mn 2+ (c) paramagnetic centers are marked with vertical bars.This journal is

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Section: Epr Resultsmentioning

confidence: 99%

On the agent role of Mn²⁺ in redirecting the synthesis of Zn(OH)₂ towards nano-ZnO with variable morphology

et al. 2016

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“…6,7 Fluorescence semiconductors offer advantages in that, as they have a broad and tunable absorption spectrum extending from the ultraviolet (UV) toward the visible (UV-Vis) region. 8 Semiconductor nanocrystals such as bulk zinc sulfate (ZnS) emits high fluorescence with a color that depends on the particle size but regrettably suffers from self-quenching effects. The doping of ZnS with other impurities such as Mn 2+ and Cd 2+ are reported to significantly reduce this intrinsic quenching behavior and at the same time enhances the fluorescence efficiency of the QDs toward the cut-off wavelength of the visible region.…”

Section: Introductionmentioning

confidence: 99%

“…The doping of ZnS with other impurities such as Mn 2+ and Cd 2+ are reported to significantly reduce this intrinsic quenching behavior and at the same time enhances the fluorescence efficiency of the QDs toward the cut-off wavelength of the visible region. 8 Interestingly, the similarity in the ionic radii and valence state of the Mn 2+ and those of Zn 2+ ions allowed for an easy substitution to take place in the host ZnS crystals. 9 The Mn 2+ ion in this regard serves as the luminescence center by providing recombination sites for the electrons and holes as charge carriers.…”

Section: Introductionmentioning

confidence: 99%

Folic acid targeted Mn:ZnS quantum dots for theranostic applications of cancer cell imaging and therapy

Bwatanglang¹,

Mohammad²,

Yusof³

et al. 2016

IJN

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In this study, we synthesized a multifunctional nanoparticulate system with specific targeting, imaging, and drug delivering functionalities by following a three-step protocol that operates at room temperature and solely in aqueous media. The synthesis involves the encapsulation of luminescent Mn:ZnS quantum dots (QDs) with chitosan not only as a stabilizer in biological environment, but also to further provide active binding sites for the conjugation of other biomolecules. Folic acid was incorporated as targeting agent for the specific targeting of the nanocarrier toward the cells overexpressing folate receptors. Thus, the formed composite emits orange–red fluorescence around 600 nm and investigated to the highest intensity at Mn 2+ doping concentration of 15 at.% and relatively more stable at low acidic and low alkaline pH levels. The structural characteristics and optical properties were thoroughly analyzed by using Fourier transform infrared, X-ray diffraction, dynamic light scattering, ultraviolet-visible, and fluorescence spectroscopy. Further characterization was conducted using thermogravimetric analysis, high-resolution transmission electron microscopy, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray fluorescence, and X-ray photoelectron spectroscopy. The cell viability and proliferation studies by means of MTT assay have demonstrated that the as-synthesized composites do not exhibit any toxicity toward the human breast cell line MCF-10 (noncancer) and the breast cancer cell lines (MCF-7 and MDA-MB-231) up to a 500 µg/mL concentration. The cellular uptake of the nanocomposites was assayed by confocal laser scanning microscope by taking advantage of the conjugated Mn:ZnS QDs as fluorescence makers. The result showed that the functionalization of the chitosan-encapsulated QDs with folic acid enhanced the internalization and binding affinity of the nanocarrier toward folate receptor-overexpressed cells. Therefore, we hypothesized that due to the nontoxic nature of the composite, the as-synthesized nanoparticulate system can be used as a promising candidate for theranostic applications, especially for a simultaneous targeted drug delivery and cellular imaging.

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“…The change observed in band gaps for pure and doped ZnS samples suggests that there is a direct energy transfer between semiconductor-excited states and the 3d levels of Mn 2+ ions [32,36]. It may be due to the sp-d spin exchange interaction between the band electrons and localized d electrons of Mn ions substituting in cation sites.…”

Section: Uv-vis Studymentioning

confidence: 94%

Effect of Mn doping on structural, optical and photocatalytic behaviors of hydrothermal Zn1−xMnxS nanocrystals

Nasser

Elhouichet

Férid

2015

Applied Surface Science

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Structural, optical and crystal field analyses of undoped and Mn2+-doped ZnS nanoparticles synthesized via reverse micelle route

Cited by 63 publications

References 44 publications

On the agent role of Mn²⁺ in redirecting the synthesis of Zn(OH)₂ towards nano-ZnO with variable morphology

On the agent role of Mn²⁺ in redirecting the synthesis of Zn(OH)₂ towards nano-ZnO with variable morphology

Folic acid targeted Mn:ZnS quantum dots for theranostic applications of cancer cell imaging and therapy

Effect of Mn doping on structural, optical and photocatalytic behaviors of hydrothermal Zn1−xMnxS nanocrystals

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Structural, optical and crystal field analyses of undoped and Mn2+-doped ZnS nanoparticles synthesized via reverse micelle route

Cited by 63 publications

References 44 publications

On the agent role of Mn2+ in redirecting the synthesis of Zn(OH)2 towards nano-ZnO with variable morphology

On the agent role of Mn2+ in redirecting the synthesis of Zn(OH)2 towards nano-ZnO with variable morphology

Folic acid targeted Mn:ZnS quantum dots for theranostic applications of cancer cell imaging and therapy

Effect of Mn doping on structural, optical and photocatalytic behaviors of hydrothermal Zn1−xMnxS nanocrystals

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On the agent role of Mn²⁺ in redirecting the synthesis of Zn(OH)₂ towards nano-ZnO with variable morphology

On the agent role of Mn²⁺ in redirecting the synthesis of Zn(OH)₂ towards nano-ZnO with variable morphology