Synthesis of N, S co-doped carbon quantum dots (N,S-CQDs) for sensitive and selective determination of mercury (Hg2+) in Oreochromis niloctus (Tilapia fish)
No Thumbnail Available
Date
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
Description
This study reported the synthesis of green-emitting N,S-doped carbon quantum dots
(N,S-CQDs) through a one-step, facile, and fast hydrothermal technique using citric
acid, glutamine, and Na2S as the carbon, nitrogen, and sulphur sources respectively.
The fluorescence efficiency of the developed nanosensor was investigated by varying
the duration of synthesis (4, 5, and 6 h). Characterization of the N-CQDs was achieved
using Fourier-Transform Infra-red Spectroscopy (FTIR), High-resolution transmission
electron microscope (HRTEM), ultraviolet–visible spectroscopy (UV–Vis), and X-Ray
diffraction analysis (XRD). The as-synthesized N,S-CQDs are small (average size of
3.45 ± 0.86 nm), spherical, and displayed green emission (535 nm) with a fluorescent
quantum yield (QY) of 10.35%. FTIR analysis reveals carboxylic, hydroxyl, and
conjugated amide functional groups. The fluorometric study showed that the developed
nanosensor was selective and sensitive towards Hg2+ ions in the midst and absence of
interfering ions with a detection limit (LOD) of 28.9 nM. The static quenching
mechanism was proposed based on lifetime and UV results. Furthermore, it was used
as a nanoprobe for Hg2+ determination in Oreochromis niloctus with recoveries of 96.7–
108.6% (RSD < 4.1%), indicating the as-synthesized N,S-CQDs have potentials as a
nanoprobe for Hg2+ determination in sea foods.
Keywords
Q Science (General), QD Chemistry