Preparation of europium complex-conjugated carbon dots for ratiometric fluorescence detection of copper(ii) ions

Abstract

In this work, by conjugating a europium complex, 4,4 0 -bis(1 00 ,1 00 ,1 00 ,2 00 ,2 00 ,3 00 ,3 00 -heptafluoro-4 00 ,6 00 -hexanedion-6 00 -yl)chlorosulfo-o-terphenyl-Eu 3+ (BHHCT-Eu 3+ ), onto the surface of carbon dots (C-dots), a new type of dual-fluorophore nanoparticle, C-dots-BHHCT-Eu 3+ , has been successfully prepared for the ratiometric fluorescence detection of Cu 2+ ions in aqueous media. The results of transmission electron microscopy (TEM) and fluorescence spectroscopy characterization indicate that the nanoparticles are monodisperse, spherical and uniform in size (B8.6 nm in diameter), and have stable and well-resolved dual-wavelength emission properties. Under excitation at 337 nm, the composite nanoparticles of C-dots-BHHCT-Eu 3+ exhibit two emission peaks at 410 nm and 615 nm, respectively. Upon the addition of Cu 2+ ions, the emission intensity of the nanoparticles at 615 nm is significantly decreased, while that at 410 nm shows no response to the addition of Cu 2+ ions. Correspondingly, the emission intensity ratio, I 615 /I 410 , shows a good linearity against the concentration of Cu 2+ ions. In addition, the investigation results of fluorescence responses of the nanoparticles to different metal ions reveal that the fluorescence response of C-dots-BHHCT-Eu 3+ to Cu 2+ ions is highly specific without interference from other metal ions. All of the results suggest that the new dual-fluorophore composite nanoparticles could be used as a ratiometric fluorescence probe for the detection of Cu 2+ ions in aqueous media with high selectivity and sensitivity.

Detection and imaging of fatty plaques in blood vessels using functionalized carbon dots

“…Similar observation has been reported earlier 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 9 also 25,35,36 . Similar observation has been reported earlier 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 9 also 25,35,36 .…”

Functionalized carbon dots enable simultaneous bone crack detection and drug deposition

“…1A) indicates that the CDs possess a spherical morphology and have an average size of 4-7 nm which matches with the earlier report. 25,31 To support this observation, DLS measurements on CDs and CDGAC were carried out. 1B).…”

Understanding the Photoluminescence Mechanism of Nitrogen‐Doped Carbon Dots by Selective Interaction with Copper Ions

“…Down and up‐conversion fluorescence based Cu 2+ detection using CDs has demonstrated a high sensitivity towards Cu 2+ but this sensor lacks selectivity . Ye et al presented the ratiometric fluorescence sensing of Cu 2+ using a CD conjugate of a europium complex . Graphitic carbon nitride nanosheets and photoluminescence polymer nanodots derived from grass are two other representative example of carbon based fluorescent probe used in the selective detection of Cu 2+ .…”