Yellow Fluorescent Carbon Dots for Selective Recognition of As³⁺ and Fe³⁺ Ions

Abstract

Measurement levels of As 3+ and Fe 3+ ions have attracted considerable research attention for environmental and living being's health safety issues. Herein, we report a green synthetic approach to prepare bright yellow fluorescent carbon dots (C-dots) from a ophenylenediamine and pyrazole mixture. A large Stokes shift of up to 145 nm was observed under an excitation wavelength of 415 nm. The metal ion sensing study affirmed that the C-dots' aqueous dispersion underwent a strong fluorescence quenching for selective As 3+ and Fe 3+ ion sensing with detection limits of 24.4 and 63.4 nM, respectively. In addition, a red shift of the C-dots' emission was noticed in the case of Fe 3+ ion incubation. Furthermore, the C-dots were coated on a simple paper strip and embedded in a solid silica aerogel porous matrix in which detection was carried out through the visible and fluorescence color changes. The quenching of the C-dots' fluorescence was ascribed to the static quenching effect, which was proved by UV−vis absorbance and time-resolved fluorescence spectroscopy techniques. In addition, this method was successfully used to detect these ions in real water samples in the presence of other contaminants. Moreover, intracellular detection of the ions has been successfully performed in living cells at a lower concentration. The methodology reported here opens a new window in real and on-site applications.

Fluorescent Polymer Carbon Dots for the Sensitive–Selective Sensing of Fe3+Metal Ions and Cellular Imaging

“…The change in absorbance in the presence of the quencher suggests static quenching instead of dynamic quenching. 26 It indicates that in the ground state, Fe 3+ ions interact with the functional groups present on the surface of FPCDs and form a stable nonfluorescent complex, leading to static quenching. 26 To confirm the static fluorescence quenching mechanism, the time-resolved photoluminescence spectra of FPCDs were monitored with and without Fe 3+ ions (Figure 7c,d).…”

“…Most of the techniques have a complicated protocol, are time-consuming and require costly instruments . 26 However, based on developments in the fluorometric detection technique has been supposed to be an easy and economic technique.…”

Covalently N-Doped MXene Quantum Dots for Highly Stable Fluorescent Cu2+ Ion Sensor

“…Currently, sensitive detection of Fe 3+ and Cu 2+ ions can be realized by various methods, such as electrochemical methods, atomic absorption spectroscopy, and inductively coupled plasma–mass spectrometry . However, these methods have some drawbacks, including expensive instruments, tedious preprocessing steps, and complex detection processes. , Fluorescent spectrophotometry has been developed for the detection of Fe 3+ and Cu 2+ ions because of advantages such as high sensitivity, simple operation, and low cost. , …”

“…6,7 Fluorescent spectrophotometry has been developed for the detection of Fe 3+ and Cu 2+ ions because of advantages such as high sensitivity, simple operation, and low cost. 8,9 MXene is a class of inorganic materials with a twodimensional (2D) structure similar to graphene and usually classified as carbide, nitride, or carbon nitride containing transition metal elements such as Ti, Zr, V, Nb, Ta, Hf, Sc, and Mo. 10,11 MXene was originally reported in 2011 and has attracted wide attention because of extraordinary characteristics including a high surface area, good conductivity, and hydrophilic properties.…”

Novel class of yellow emitting carbon dots stimulate collective cell migration and 3D uptake in vivo

“…The yellow fluorescent CDs synthesized show maximum emission at 415 nm excitation wavelength and have a quantum yield of 10.3% used for heavy metal sensing in water samples. 6 Xiaojuan et al have synthesized yellow fluorescent phosphorus and nitrogen co-doped CDs from pumpkin peel and phosphoric acid (H 3 PO 4 ) with satisfactory quantum yield and used them for bioimaging purposes. 7 Although very few yellow fluorescent CDs have been reported, the synthesis method is tedious or the product obtained is in small amount, limiting the use of CDs for bioimaging purposes.…”