scholarly journals A Novel Surfactant Sensitized Fluorescent Sensor for Co(II) Based on Nitrogen Doped Carbon Quantum Dots

2021 ◽  
Author(s):  
Ouwen Xu ◽  
Wei Liu ◽  
Jiawei Li ◽  
Shuyu Wan ◽  
Xiashi Zhu
Keyword(s):  
Quantum Dots ◽  
Fluorescence Quenching ◽  
Limit Of Detection ◽  
Fluorescent Sensor ◽  
Sodium Dodecyl ◽  
Carbon Quantum Dots ◽  
Quenching Effect ◽  
Nitrogen Doped ◽  
Nitrogen Doped Carbon

AbstractA novel nitrogen-doped carbon quantum dots (N-CDs) were prepared by the microwave irradiation method. The fluorescence quenching effect of Co(II) on the N-CDs was studied in the sodium dodecyl sulfate (SDS) medium and the fluorescence quenching was sensitized in the SDS. The linear range of calibration curve for the determination of Co(II) was 0.17µg/mL-11.8µg/mL and the limit of detection was 0.052µg/mL. The method has been applied for the determination of Co(II) in samples with satisfactory results.

scholarly journals Facile Synthesis of Nitrogen-Doped Carbon Quantum Dots with Chitosan for Fluorescent Detection of Fe3+

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1731 ◽  
Author(s):  
Zhao ◽  
Wang ◽  
Zhao ◽  
Deng ◽  
Xia
Keyword(s):  
Quantum Dots ◽  
Fluorescent Sensor ◽  
Nitrogen Sources ◽  
Carbon Quantum Dots ◽  
Fluorescent Detection ◽  
Excitation Wavelength ◽  
Environmental Application ◽  
Quenching Effect ◽  
Nitrogen Doped ◽  
Nitrogen Doped Carbon

A facile, economical, and one-step hydrothermal method was used to prepare highly luminescent nitrogen-doped carbon quantum dots (N-CQDs) with chitosan as both carbon and nitrogen sources. The as-prepared N-CQDs have an average size of 2 nm and exhibit excitation wavelength-dependent fluorescence with a maximum excitation and emission at 330 and 410 nm, respectively. Furthermore, due to the effective quenching effect of Fe3+ ions, the prepared N-CQDs can be used as a fluorescent sensor for Fe3+ ion-sensitive detection with a detection limit of 0.15 μM. The selectivity experiments revealed that the fluorescent sensor is specific to Fe3+ even with interference by high concentrations of other metal ions. Most importantly, the N-CQD-based Fe3+ ion sensor can be successfully applied to the determination of Fe3+ in real water samples. With excellent sensitivity and selectivity, such stable and cheap carbon materials are potentially suitable for the monitoring of Fe3+ in environmental application.

scholarly journals Synthesis and Properties of Nitrogen-Doped Carbon Quantum Dots Using Lactic Acid as Carbon Source

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 466
Author(s):  
Kaixin Chang ◽  
Qianjin Zhu ◽  
Liyan Qi ◽  
Mingwei Guo ◽  
Woming Gao ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Lactic Acid ◽  
Fluorescence Quenching ◽  
Functional Groups ◽  
Fluorescence Intensity ◽  
Carbon Quantum Dots ◽  
Nitrogen Doped ◽  
Ph Values ◽  
Wide Range ◽  
Nitrogen Doped Carbon

Nitrogen-doped carbon quantum dots (N-CQDs) were synthesized in a one-step hydrothermal technique utilizing L-lactic acid as that of the source of carbon and ethylenediamine as that of the source of nitrogen, and were characterized using dynamic light scattering, X-ray photoelectron spectroscopy ultraviolet-visible spectrum, Fourier-transformed infrared spectrum, high-resolution transmission electron microscopy, and fluorescence spectrum. The generated N-CQDs have a spherical structure and overall diameters ranging from 1–4 nm, and their surface comprises specific functional groups such as amino, carboxyl, and hydroxyl, resulting in greater water solubility and fluorescence. The quantum yield of N-CQDs (being 46%) is significantly higher than that of the CQDs synthesized from other biomass in literatures. Its fluorescence intensity is dependent on the excitation wavelength, and N-CQDs release blue light at 365 nm under ultraviolet light. The pH values may impact the protonation of N-CQDs surface functional groups and lead to significant fluorescence quenching of N-CQDs. Therefore, the fluorescence intensity of N-CQDs is the highest at pH 7.0, but it decreases with pH as pH values being either more than or less than pH 7.0. The N-CQDs exhibit high sensitivity to Fe3+ ions, for Fe3+ ions would decrease the fluorescence intensity of N-CQDs by 99.6%, and the influence of Fe3+ ions on N-CQDs fluorescence quenching is slightly affected by other metal ions. Moreover, the fluorescence quenching efficiency of Fe3+ ions displays an obvious linear relationship to Fe3+ concentrations in a wide range of concentrations (up to 200 µM) and with a detection limit of 1.89 µM. Therefore, the generated N-CQDs may be utilized as a robust fluorescence sensor for detecting pH and Fe3+ ions.

Highly luminescent nitrogen-doped carbon quantum dots as effective fluorescent probes for mercuric and iodide ions

2015 ◽  
Vol 3 (9) ◽  
pp. 1922-1928 ◽  
Author(s):  
Zi Li ◽  
Huijun Yu ◽  
Tong Bian ◽  
Yufei Zhao ◽  
Chao Zhou ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Fluorescence Quenching ◽  
Fluorescent Probes ◽  
Hydrothermal Reaction ◽  
Carbon Quantum Dots ◽  
Iodide Ions ◽  
Nitrogen Doped ◽  
Recovery Processes ◽  
One Step ◽  
Nitrogen Doped Carbon

Nitrogen-doped carbon quantum dots (N-CQDs) prepared via a one-step hydrothermal reaction exhibited highly selective and sensitive detection of Hg2+ and I− through fluorescence quenching and recovery processes, respectively.

A nitrogen doped carbon quantum dot-enhanced chemiluminescence method for the determination of Mn2+

2018 ◽  
Vol 10 (5) ◽  
pp. 541-547 ◽  
Author(s):  
Junmei Zhang ◽  
Xiaoxia Chen ◽  
Yue Li ◽  
Suqin Han ◽  
Yao Du ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Ascorbic Acid ◽  
Ultrasonic Method ◽  
Carbon Quantum Dots ◽  
Chemiluminescence Method ◽  
Nitrogen Doped ◽  
Carbon Quantum Dot ◽  
Enhanced Chemiluminescence ◽  
Nitrogen Doped Carbon

Nitrogen doped carbon quantum dots (NCQDs) were synthesized via an ultrasonic method with ascorbic acid as the carbon source and ammonia as the nitrogen source.

scholarly journals Detection of 2,4-Dinitrophenol and Bio-Imaging Application with Agaric-Based Nitrogen-Doped Carbon Quantum Dots (N-CQDs)

2021 ◽  
Author(s):  
Jiao Zhao ◽  
Xianhao Long ◽  
Zhihua Li ◽  
Yujiao Tu
Keyword(s):  
Quantum Dots ◽  
Fluorescence Probe ◽  
Ph Value ◽  
Limit Of Detection ◽  
Carbon Quantum Dots ◽  
Coefficient Of Determination ◽  
Nitrogen Doped ◽  
Chemical Structures ◽  
Bio Imaging ◽  
Nitrogen Doped Carbon

With agaric as carbon source and urea as nitrogen source, this paper has successfully synthesized nitrogen-doped carbon quantum dots (N-CQDs) by simple one-step hydrothermal method. A series of analysis have been used to make characterization of the physical, chemical structures and optical performance of N-CQDs. The fluorescence stability was studied by examining the ionic strength, pH value and storage time and other conditions. The cytotoxicity and bacterial toxicity of N-CQDs were applied to biological imaging. Considering the quenching effect of 2,4-dinitrophenol (2,4‑DNP) on the fluorescence generated by N-CQDs, N-CQDs have been used as fluorescence probe in detection of 2,4-DNP where N-CQDs showed high sensitivity, selectivity and strong disturbance resistance to 2,4-DNP based on the quenching mechanism of transfer of resonance energy. It can also be concluded that agaric-based N-CQDs can be used in bio-imaging due to a good inhibitory effect on but low toxicity to bacteria. Under the optimal experimental conditions, the probe has presented a good coefficient of determination (R2 = 0.9969) and a low limit of detection (15.78 nM). This method has been successfully applied to determine 2,4-DNP in environmental samples and provided a new idea for developing green and natural composite carbon materials.

A novel electrochemiluminescent immunosensor based on the quenching effect of aminated graphene on nitrogen-doped carbon quantum dots

2015 ◽  
Vol 889 ◽  
pp. 82-89 ◽  
Author(s):  
Jing Zhou ◽  
Tongqian Han ◽  
Hongmin Ma ◽  
Tao Yan ◽  
Xuehui Pang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Carbon Quantum Dots ◽  
Quenching Effect ◽  
Nitrogen Doped ◽  
Nitrogen Doped Carbon
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