Mercury(II) sensing based on the quenching of fluorescence of CdS-dendrimer nanocomposites

• Type: Article in International Scientific Journal
• Date: 2009

Authors

Bruno B Campos (Author) Other; Manuel Algarra (Author) Other; Beatriz Alonso (Author) Other; Carmen M Casado (Author) Other; Joaquim C G E Esteves da Silva (Author) FCUP

Journal

Title: The Analyst

Vol. 134

Pages: 2447-2452

ISSN: 0003-2654

Publisher: Royal Society of Chemistry

Indexing

ISI Web of Knowledge - 46 Citations

Scopus - 49 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-003-P2F

DOI: 10.1039/b914302e

Abstract (EN): A chemical sensor for mercury(II) (Hg(II)) was developed based on the quenching of the fluorescence of cadmium sulfide (CdS) quantum dots (QDs) coated with polypropylenimine tetrahexacontaamine dendrimer ( DAB) generation 5, CdS-DAB nanocomposites. The synthesis and characterization of CdS-DAB nanocomposites by means of EDXA, SEM and steady state luminescence is described. Macroscopic spherical structures are observed by electronic microscopy and the wavelength for the maximum fluorescence emission occurs at 535 nm (excitation at 351 nm). Stern-Volmer plots show a linear response in the range of 1 x 10(-6) to 1 x 10(-5) M with a quenching constant (K(sv)) of 1.5 x 10(5) M(-1). A parallel factor (PARAFAC) analysis model confirmed that Hg( II) alone provokes quenching of the fluorescence. Cu(II) and Pb(II) also quench the fluorescence of CdS-DAB nanocomposites, with a K(sv) = 1.9 x 10(5) M(-1) and K(sv) = 2.2 x 10(-4) M(-1), respectively, and Cd(II), Zn(II), Co(II) and Ni(II) have no effect. Ionic strength, in the range from 1.25 x 10(-3) up to 2 M, provokes a shift in the wavelength of the maximum of the emission spectra, from 482 to 677 nm.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 6