Graphitic carbon nitride quantum dots as an “off-on” fluorescent switch for determination of mercury(II) and sulfide

Wang, Xuan; Yang, Xuefang; Wang, Ning; Lv, Junjie; Wang, Haojiang; Choi, Martin M. F.; Bian, Wei

doi:10.1007/s00604-018-2994-0

Cited by 34 publications

(14 citation statements)

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“…Figure 2d depicts the UV-vis spectra and fluorescence spectra of N, S-GQDs in the absence and presence of Fe 3+ or Hg 2+ , respectively. The absorption threshold and peak position change cannot be observed, which indicates that no stable metal complexes form [36]. It is noticeable that the absorption spectra of N, S-GQDs with Fe 3+ have overlaps with the emission and excitation spectra of N, S-GQDs, which is related to the characteristic of IFE quenching [7,33].…”

Section: Resultsmentioning

confidence: 99%

The Fluorescent Quenching Mechanism of N and S Co-Doped Graphene Quantum Dots with Fe3+ and Hg2+ Ions and Their Application as a Novel Fluorescent Sensor

et al. 2019

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The fluorescence intensity of N, S co-doped graphene quantum dots (N, S-GQDs) can be quenched by Fe3+ and Hg2+. Density functional theory (DFT) simulation and experimental studies indicate that the fluorescence quenching mechanisms for Fe3+ and Hg2+ detection are mainly attributed to the inner filter effect (IFE) and dynamic quenching process, respectively. The electronegativity difference between C and doped atoms (N, S) in favor to introduce negative charge sites on the surface of N, S-GQDs leads to charge redistribution. Those negative charge sites facilitate the adsorption of cations on the N, S-GQDs’ surface. Atomic population analysis results show that some charge transfer from Fe3+ and Hg2+ to N, S-GQDs, which relate to the fluorescent quenching of N, S-GQDs. In addition, negative adsorption energy indicates the adsorption of Hg2+ and Fe2+ is energetically favorable, which also contributes to the adsorption of quencher ions. Blue fluorescent N, S-GQDs were synthesized by a facile one-pot hydrothermal treatment. Fluorescent lifetime and UV-vis measurements further validate the fluorescent quenching mechanism is related to the electron transfer dynamic quenching and IFE quenching. The as-synthesized N, S-GQDs were applied as a fluorescent probe for Fe3+ and Hg2+ detection. Results indicate that N, S-GQDs have good sensitivity and selectivity on Fe3+ and Hg2+ with a detection limit as low as 2.88 and 0.27 nM, respectively.

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Section: Resultsmentioning

confidence: 99%

The Fluorescent Quenching Mechanism of N and S Co-Doped Graphene Quantum Dots with Fe3+ and Hg2+ Ions and Their Application as a Novel Fluorescent Sensor

et al. 2019

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“…Different fluorimetric methods for the estimation of mercury have been reported previously. [13,14,26] Varying drawbacks were reported in published methods such as being time-consuming methods with a long time for preparation for the quantum dots (1-10 h), as well as heat consuming, a low QY, and a lack of sensitivity, with LOQs of 0.004, 0.001, and 0.84 μg mL À1 , [13,14,26] respectively. However, the presented method is ultrasensitive with an LOD of 0.0003 μg mL À1 , is environmentally friendly, time saving, and has a high QY 40.26% (Table 5).…”

Section: Comparison Study Between Presented Work and Other Reported M...mentioning

confidence: 99%

Ultrasensitive green spectrofluorimetric approach for quantification of Hg(II) in environmental samples (water and fish samples) using cysteine@MnO₂ dots

et al. 2023

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Mercury (Hg2+) is a natural element present in foods such as fish, water and soil. Exposure to mercury leads to severe toxic effects on the nervous, digestive, and immune systems. Here, a novel, green, and environmentally friendly fluorescent probe decorated with cysteine/MnO2 quantum dots (Cys@MnO2 QDs) was synthesized. This synthesis was carried out using a simple ultrasound technique with the aid of cysteine for fabricating Cys@MnO2 QDs to estimate Hg levels in fish and water samples. In this morphological study, Cys@MnO2 QDs were fully characterized using high‐resolution transmission electron microscopy, zeta potential analysis, fluorescence, ultraviolet–visible and infrared spectroscopy. The fluorescence of the synthesized Cys@MnO2 QDs was significantly quenched by gradually increasing the Hg(II) concentration. The quenching mechanism based on the Hg–S bonds strengthened the utility of the Cys@MnO2 QDs as a novel luminescent nanoprobe. The estimation of Hg was linear in the concentration range 0.7–100.0 ng mL−1 with a limit of quantitation equal to 0.30 ng mL−1. The Cys@MnO2 QDs are fluorescent probes with various benefits such as speed, ease of use, cost‐ effective, and being environmentally friendly; they are easily applied in food manufacturing and for public health improvement.

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“…[63] The change in the peak position and threshold of absorption in the case of Hg 2 + is not observed indicating that no stable metal complexes are formed. [64] It is noticeable that the absorption spectra of Hg 2 + /Mcqd has no change in the absorption spectra…”

Section: Possible Mechanism For Sensing Of Of Hg 2 + and Cr 6 + Ions ...mentioning

confidence: 95%

Chemical Fabrication of Efficient Blue‐luminescent Carbon Quantum Dots from Coal Washery Rejects (Waste) for Detection of Hg²⁺ and Cr⁶⁺ Ions in Water

Boruah

Saikia

2022

ChemistrySelect

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An economical facile method was established for the preparation of luminescent carbon quantum dots (CQDs) by utilizing the waste coal washery rejects as precursor materials. The derived CQDs were extensively characterized for their physiochemical properties and they (Mcqds and Dcqds) show an efficient maximum quantum yield of 11 % with an average particle size of 2.5-3.0 nm. The derived CQDs exhibited better physical and chemical properties at maximum excitation and emission wavelengths of 360 nm and 450 nm, respectively, with blue-light emission. The as-synthesized CQDs (Mcqds) were applied as a fluorescent sensing probe for sensitive detection of Hg 2 + and Cr 6 + ions in water samples, showing reasonable limit of detection and quantification with recovery percentage of 96-100 %. The study has shown potential for using such cheap waste-material derived CQDs as for further development of sensing devices in future.[a] A. Boruah

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Graphitic carbon nitride quantum dots as an “off-on” fluorescent switch for determination of mercury(II) and sulfide

Cited by 34 publications

References 50 publications

The Fluorescent Quenching Mechanism of N and S Co-Doped Graphene Quantum Dots with Fe3+ and Hg2+ Ions and Their Application as a Novel Fluorescent Sensor

The Fluorescent Quenching Mechanism of N and S Co-Doped Graphene Quantum Dots with Fe3+ and Hg2+ Ions and Their Application as a Novel Fluorescent Sensor

Ultrasensitive green spectrofluorimetric approach for quantification of Hg(II) in environmental samples (water and fish samples) using cysteine@MnO₂ dots

Chemical Fabrication of Efficient Blue‐luminescent Carbon Quantum Dots from Coal Washery Rejects (Waste) for Detection of Hg²⁺ and Cr⁶⁺ Ions in Water

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Graphitic carbon nitride quantum dots as an “off-on” fluorescent switch for determination of mercury(II) and sulfide

Cited by 34 publications

References 50 publications

The Fluorescent Quenching Mechanism of N and S Co-Doped Graphene Quantum Dots with Fe3+ and Hg2+ Ions and Their Application as a Novel Fluorescent Sensor

The Fluorescent Quenching Mechanism of N and S Co-Doped Graphene Quantum Dots with Fe3+ and Hg2+ Ions and Their Application as a Novel Fluorescent Sensor

Ultrasensitive green spectrofluorimetric approach for quantification of Hg(II) in environmental samples (water and fish samples) using cysteine@MnO2 dots

Chemical Fabrication of Efficient Blue‐luminescent Carbon Quantum Dots from Coal Washery Rejects (Waste) for Detection of Hg2+ and Cr6+ Ions in Water

Contact Info

Product

Resources

About

Ultrasensitive green spectrofluorimetric approach for quantification of Hg(II) in environmental samples (water and fish samples) using cysteine@MnO₂ dots

Chemical Fabrication of Efficient Blue‐luminescent Carbon Quantum Dots from Coal Washery Rejects (Waste) for Detection of Hg²⁺ and Cr⁶⁺ Ions in Water