Fluorescent Properties of a Hybrid Cadmium Sulfide-Dendrimer Nanocomposite and its Quenching with Nitromethane

• Tipo: Artigo em Revista Científica Internacional
• Data: 2010

Autores

campos, bb (Autor) Outra; algarra, m (Autor) Outra; da silva, jcge (Autor) FCUP

Revista

Título: Journal of Fluorescence

Vol. 20

Páginas: 143-151

ISSN: 1053-0509

Editora: Springer Nature

Indexação

ISI Web of Knowledge - 26 Citações

Scopus - 35 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Ciências biológicas

CORDIS: Ciências Físicas > Química > Química analítica > Espectroquímica ; Ciências Físicas > Química > Quimíca inorgânica

Outras Informações

ID Authenticus: P-003-BMV

DOI: 10.1007/s10895-009-0532-5

Abstract (EN): A fluorescent hybrid cadmium sulphide quantum dots (QDs) dendrimer nanocomposite (DAB-CdS) synthesised in water and stable in aqueous solution is described. The dendrimer, DAB-G5 dendrimer (polypropylenimine tetrahexacontaamine) generation 5, a diaminobutene core with 64 amine terminal primary groups. The maximum of the excitation and emission spectra, Stokes' shift and the emission full width of half maximum of this nanocomposite are, respectively: 351, 535, 204 and 212 nm. The fluorescence time decay was complex and a four component decay time model originated a good fit (chi = 1.20) with the following lifetimes: tau (1) = 657 ps; tau (2) = 10.0 ns; tau (3) = 59.42 ns; and tau (4) = 265 ns. The fluorescence intensity of the nanocomposite is markedly quenched by the presence of nitromethane with a dynamic Stern-Volmer constant of 25 M(-1). The quenching profiles show that about 81% of the CdS QDs are located in the external layer of the dendrimer accessible to the quencher. PARAFAC analysis of the excitation emission matrices (EEM) acquired as function of the nitromethane concentration showed a trilinear data structure with only one linearly independent component describing the quenching which allows robust estimation of the excitation and emission spectra and of the quenching profiles. This water soluble and fluorescent nanocomposite shows a set of favourable properties to its use in sensor applications.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 9