Journal
NANOMATERIALS
Volume 12, Issue 3, Pages -Publisher
MDPI
DOI: 10.3390/nano12030385
Keywords
sensor; fluorescence; ratiometric; silver; mercury; carbon dots; europium
Categories
Funding
- POCI
- FCT
- FEDER [LISBOA-01-0145-FEDER-029319, PTDC/NAN-MAT/29317/2017, UIDB/00100/2020, PD/BD/127905/2016]
Ask authors/readers for more resources
Carbon dots doped with Eu3+ ions were synthesized and their interaction and luminescence properties were characterized by vibrational spectroscopy and UV-vis excitation spectroscopy. The Eu3+ ions are strongly coordinated with the carboxylate groups at the surface of the Cdots and incorporated within the nanographene network in the carbon core. The luminescence of the Cdots is strongly quenched by Hg2+ and Ag+, and a ratiometric sensor can be built using their luminescence intensities ratio.
Carbon dots doped with Eu3+ ions (Eu-Cdots) were prepared by a hydrothermal treatment, using citric acid and urea as precursors and Eu (NO3)(3) as a europium source. The Eu3+ ions are strongly coordinated with the carboxylate groups at the surface of the Cdots and incorporated within the nanographene network in the carbon core. Vibrational spectroscopy provides evidence of such interaction with identification of bands assigned to the stretching of the Eu-O bond. Eu3+ doped Cdots have larger diameters then undoped Cdots, but they are divided into smaller domains of sp(2) carbon. The UV-vis excitation spectrum provides evidence of energy transfer from the Cdots to the Eu3+. The luminescence spectrum shows the characteristic sharp peaks of Eu3+ in the red part of the visible spectrum and a broad emission of Cdots centered at 450 nm. The luminescence of the Cdots is strongly quenched by Hg2+ and Ag+, but not by other cations. The quenching mechanism differs significantly depending on the nature of the ion. Both the blue emission of Cdots and the red emission of Eu3+ are quenched in the presence of Hg2+ while only the emission of the Cdots is affected by the presence of Ag+. A ratiometric sensor can be built using the ratio of luminescence intensities of the Cdots to the Eu3+ peaks.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available