Carbon Dots Based Dual-Emission Silica Nanoparticles as a Ratiometric Nanosensor for Cu²⁺

Abstract

A simple and effective strategy for designing ratiometric fluorescent nanosensor has been described in this work. A carbon dots (CDs) based dual-emission nanosensor for Cu(2+) detection was prepared by coating CDs on the surface of Rhodamine B-doped silica nanoparticles. The fluorescent CDs were synthesized using N-(β-aminoethyl)-γ-aminopropyl methyldimethoxysilane (AEAPMS) as the main raw material, so that the residual ethylenediamine groups and methoxysilane groups on the surface of CDs can serve as the Cu(2+) recognition sites and the silylation reaction groups. The obtained nanosensor showed characteristic fluorescence emissions of Rhodamine B (red) and CDs (blue) under a single excitation wavelength. Upon binding to Cu(2+), only the fluorescence of CDs was quenched, resulting in the ratiometric fluorescence response of the dual-emission silica nanoparticles. This ratiometric nanosensor exhibited good selectivity to Cu(2+) over other substances, such as metal ions, amino acids, proteins, and vitamin C. The ratio of F467/F585 linearly decreased with the increasing of Cu(2+) concentration in the range of 0 to 3 × 10(-6) M, a detection limit as low as 35.2 nM was achieved. Additionally, this nanosensor was successfully applied for the ratiometric fluorescence imaging of Cu(2+) in cells and determination of Cu(2+) in real tap water.

Carbon Based Dots and Their Luminescent Properties and Analytical Applications

“…The nanohybrid was successfully applied for imaging and biosensing of Cu 2+ ions in living cells. A similar work was carried out by Liu and coworkers [236]. CDs were coated on the surface of Rhodamine B-doped silica nanoparticles by the silylation reaction.…”

Polyethyleneimine-templated copper nanoclusters via ascorbic acid reduction approach as ferric ion sensor

“…3. Considering that interaction of Cu 2+ with a high concentration of would occur when the pH was higher than 10.0 [38], the optimal pH value of BPEI was chosen to 10.0 for the formation of the BPEI-CuNCs.…”

Highly selective detection of Hg2+ and MeHgI by di-pyridin-2-yl-[4-(2-pyridin-4-yl-vinyl)-phenyl]-amine and its zinc coordination polymer

“…[19][20][21][22][23][24][25][26] These single intensitybased detectors are usually compromised by other metal ions, the concentration change of sensors, drift of light source, and environmental effects. 27 In this regard, ratiometric fluorescence chemosensors are attractive candidates for the detection of mercury ions. Such sensors undergo a color change in response to the analyte, with the change in emission wavelength correlated to analyte concentration, enabling quantitative detection.…”