Hg(II) sensing based on functionalized carbon dots obtained by direct laser ablation
Hg(II) sensing based on functionalized carbon dots obtained by direct laser ablation
dc.contributor.author | Helena Gonçalves | en |
dc.contributor.author | Joaquim Esteves da Silva | en |
dc.contributor.author | Pedro Jorge | en |
dc.contributor.author | José Ramiro Fernandes | en |
dc.date.accessioned | 2017-11-16T12:51:48Z | |
dc.date.available | 2017-11-16T12:51:48Z | |
dc.date.issued | 2010 | en |
dc.description.abstract | The synthesis of carbon nanoparticles obtained by direct laser ablation [UV pulsed laser irradiation(248 nm, KrF)] of carbon targets immersed in water is described. Laser ablation features were optimized to produce carbon nanoparticles with dimensions up to about 100 nm. After functionalization with NH2–polyethylene-glycol (PEG200) and N-acetyl-l-cysteine (NAC) the carbon nanoparticles become fluorescent with excitation and emission wavelengths at 340 and 450 nm, respectively. The fluorescence decay time was complex and a three-component decay time model originated a good fit (x= 1.09) with the following lifetimes: t1 = 0.35 ns; t2 = 1.8 ns; and t3 = 4.39 ns. The fluorescence of the carbon dots is sensitive to pH with an apparent pKa = 4.2. The carbon dots were characterized by 1H NMR and HSQC and the results show an interaction between PEG200 and the carbon surface as well as a dependence of the chemical shift with the reaction time. The fluorescence intensity of the nanoparticles is quenched by the presence of Hg(II) and Cu(II) ions with a Stern–Volmer constant (pH = 6.8) of 1.3×105 and 5.6×104M−1, respectively. As such the synthesis and application of a novel biocompatible nanosensor for measuring Hg(II) is presented. | en |
dc.identifier.uri | http://repositorio.inesctec.pt/handle/123456789/1822 | |
dc.language | eng | en |
dc.relation | 3294 | en |
dc.relation | 3565 | en |
dc.rights | info:eu-repo/semantics/openAccess | en |
dc.title | Hg(II) sensing based on functionalized carbon dots obtained by direct laser ablation | en |
dc.type | article | en |
dc.type | Publication | en |