Green-emitting carbon quantum dots as efficient fluorescent probes for Cu<SUP>2 </SUP> and EDTA detection by " turn-on-off " strategy

Key Words:SENSITIVE DETECTION; SELECTIVE DETECTION; COPPER IONS; METAL-IONS; NITROGEN; CELL; NANODOTS; HG2 ; SENSOR

Abstract:Copper is essential for human body because it plays an important role in ious physiological processes, so the sensitive detection of Cu 2 ions is a vital topic in human health and environment safe. In this work, greenemitting carbon quantum dots (CQDs) facilely synthesized by a microwave -assisted hydrothermal method were used as fluorescent probes for Cu 2 detection. The CQDs showed a rapid and sensitive response to Cu 2 with a color change and brightened fluorescence. The fluorescence enhancement of CQDs reaches 4.51 -fold by 5 mu M Cu 2 as a typical "turn -on" strategy. A good linear relation of the fluorescence enhancement by Cu 2 appears in a range of 0.1-1 mu M Cu 2 with a limit of detection (LOD) of 2.46 nM. Then, the enhanced fluorescence of Cu 2 -CQDs could be rapidly decreased by EDTA via a quenching response ("turn-off"). A linear range of the fluorescence decrease and EDTA concentration is 1-10 mu M with a LOD of 0.19 mu M. The interference experiments for the detections of both Cu 2 and EDTA show a high selectivity. The practical detections of both Cu 2 and EDTA in actual water samples and spiked samples demonstrated good reproducibility and effective recovery rates. In addition, the Cu 2 -CQDs even had a slow "turn-off" response to histidine over 20 natural amino acids. Overall, the CQDs-based "turn -on -off" detection methods with high sensitivity and selectivity in this work can be considered a promising new choice for the fluorescence analysis of Cu 2 and EDTA.

Volume:693

Issue:

Translation or Not:no