Molecular fluorescence in silica nanoparticles doped with quercetin and rhodamine B / Fluorescência molecular em nanopartículas de sílica marcadas com quercetina e rodamina B

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Silica nanospheres doped with quercetin-Al+3 and rhodamine B were synthesized with high size control and morphology, using acid and basic catalysis of tetraethylorthosilicate (TEOS). The nanoparticle diameter obtained was about 200- 300 nm, with higher regularity when synthesized in alkaline media. The Stöbers and core-shell methods were used as preparation methods. Because the alkaline hydrolysis of quercetin, the flavonoid or the quercetin-Al+3 complex doped nanoparticles showed higher emission intensity when acid catalysis was used. When basic catalysis was performed, the particles prepared with an alumina-sol showed expressive emission intensity, but nanometric parallelepipeds were obtained. The quercetin-alumina fluorescence decays are biexponential, agreeing with the two types of quercetin-Al+3 complexes formed in the nanoparticles domain. In the case of rhodamine B, fluorescence correlation spectroscopy (FCS) measurements were performed, showing a relation between diffusion relaxation with size and aggregation behavior.

ASSUNTO(S)

alkaline hydrolysis hidrólise alcalina silica nanoparticles fluoróforos nanopartículas de sílica fluorescence spectroscopy espectroscopia de fluorescência fluorophores

ACESSO AO ARTIGO

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