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1.
J Nanosci Nanotechnol ; 20(2): 701-708, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31383065

RESUMO

In the present study we developed novel luminescent magnetic nanocomposites termed Fe3O4@polyaniline/carbon dots. First, Fe3O4 magnetic nanoparticles were prepared by the coprecipitation method. The nanoparticles were then coated with polyaniline using the in situ growth method to form Fe3O4@polyaniline nanohybrids, which were endowed with amino functional groups on the surface and avoided the aggregation of Fe3O4 nanoparticles. The X-ray diffraction pattern demonstrated that the crystalline phase of the Fe3O4 nanoparticles was an inverse spinel structure and was not changed in the Fe3O4@polyaniline nanohybrids. The saturation magnetization and the coercive force of the as-prepared Fe3O4@polyaniline nanohybrids measured by a vibrating sample magnetizer were 63.7 emu·g-1 and zero respectively, which indicated that the Fe3O4@polyaniline nanohybrids exhibited excellent superparamagnetism. The Fe3O4@polyaniline nanohybrids were conjugated with carbon dots, prepared from orange juice, via the amide bond between the amino groups on the surface of the Fe3O4@polyaniline nanohybrids and the carboxyl groups on the surface of carbon dots. The obtained luminescent magnetic nanocomposites Fe3O4@polyaniline/carbon dots showed good photoluminescent properties, which hinted that the nanocomposites have potential in drug tracing and magnetic targeted drug delivery. Finally, the anticancer drug methotrexate was loaded into the Fe3O4@polyaniline/carbon dots nanocomposites, forming a novel magnetic targeted drug delivery system. The results confirmed that the novel drug delivery system exhibited excellent drug-loading capability for methotrexate of ca. 70%, and emits strong fluorescence at the wavelength of 360 nm. An in vitro release experiment of the drug delivery system indicated that the cumulative release percentage of methotrexate was 17.2% in the phosphate-buffered saline (pH = 7.4) within 36 h.

2.
Chem Commun (Camb) ; 53(23): 3357-3360, 2017 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-28261715

RESUMO

Novel Cu-In-S quantum dots (CIS QDs), which exhibit interesting aggregation-induced emission (AIE) properties, were successfully prepared via a hydrothermal method. When the solvent was changed from water to 90 vol% DMSO, the photoluminescence intensity of the as-prepared CIS QDs was enhanced about 126-fold.

3.
Luminescence ; 30(7): 1133-8, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25716774

RESUMO

A novel and sensitive method for the determination of ceftazidime and cefepime in an active pharmaceutical ingredient (API) has been developed based on the fluorescence quenching of poly(ethylene glycol) (PEG)2000-capped carbon quantum dots (CQDs) prepared using a chemical oxidation method. The quenching of fluorescence intensity is proportional to the concentration of ceftazidime and cefepime over the range of 0.33-3.30 and 0.24-2.40 µg/mL, respectively. The mode of interaction between PEG2000-capped CQDs and ceftazidime/cefepime in aqueous solutions was investigated using a fluorescence, UV/Vis and Fourier transform infrared spectrometry (FTIR) at physiological pH. UV/Vis and FTIR spectra demonstrated that ground state compounds were formed through hydrophobic interaction the fluorescence quenching of CQDs caused by ceftazidime and cefepime. The quenching constants decreased with increases in temperature, which was consistent with static quenching.


Assuntos
Carbono/química , Ceftazidima/análise , Cefalosporinas/análise , Fluorescência , Pontos Quânticos , Cefepima , Conformação Molecular , Polietilenoglicóis/química , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier
4.
Luminescence ; 30(3): 362-70, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25060390

RESUMO

The interactions between thioglycolic acid-capped-CuInS2 /ZnS quantum dots (CuInS2 /ZnS/TGA QDs) and tyrosine kinase inhibitor (TKI) were investigated using fluorescence, ultraviolet-visible spectrometry and Fourier transform infrared spectrometry. The results indicated that the fluorescence intensity of CuInS2 /ZnS/TGA could be quenched by imatinib, dasatinib, nilotinib, gefitinib and erlotinib, which hinted that CuInS2 /ZnS/TGA QDs could be used in the detection of TKI in active pharmaceutical ingredients (API). Calibration curves showed good linear correlation and low detection limits. The average recovery was between 98 and 102%. Moreover, the nature of the fluorescence quenching mechanism of CuInS2 /ZnS/TGA QDs by TKI was discussed. A ground state complex was formed by hydrogen bonding between the carboxyl group of CuInS2 /ZnS/TGA QDs and the amino group of TKI. This led to an increase in non-radiative transition and fluorescence quenching of CuInS2 /ZnS/TGA QDs.


Assuntos
Inibidores de Proteínas Quinases/análise , Proteínas Tirosina Quinases/antagonistas & inibidores , Pontos Quânticos/química , Sulfetos/química , Compostos de Zinco/química , Sítios de Ligação , Cobre/química , Fluorescência , Corantes Fluorescentes/química , Ligações de Hidrogênio , Índio/química , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/metabolismo , Espectrometria de Fluorescência/métodos , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura Ambiente , Tioglicolatos/química
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