Red-fluorescent graphene quantum dots from guava leaf as a turn-off probe for sensing aqueous Hg(ii)

2021 ◽  
Vol 45 (10) ◽  
pp. 4617-4625
Author(s):  
Rahul V. Khose ◽  
Goutam Chakraborty ◽  
Mahesh P. Bondarde ◽  
Pravin H. Wadekar ◽  
Alok K. Ray ◽  
...  

In this work, we have prepared red-fluorescent graphene quantum dots and utilized as a highly selective and sensitive fluorescence turn-off probe for detection of the toxic metal ion Hg2+ from guava leaf extract.

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3850 ◽  
Author(s):  
Nur Ain Asyiqin Anas ◽  
Yap Wing Fen ◽  
Nur Alia Sheh Omar ◽  
Wan Mohd Ebtisyam Mustaqim Mohd Daniyal ◽  
Nur Syahira Md Ramdzan ◽  
...  

About 71% of the Earth’s surface is covered with water. Human beings, animals, and plants need water in order to survive. Therefore, it is one of the most important substances that exist on Earth. However, most of the water resources nowadays are insufficiently clean, since they are contaminated with toxic metal ions due to the improper disposal of pollutants into water through industrial and agricultural activities. These toxic metal ions need to be detected as fast as possible so that the situation will not become more critical and cause more harm in the future. Since then, numerous sensing methods have been proposed, including chemical and optical sensors that aim to detect these toxic metal ions. All of the researchers compete with each other to build sensors with the lowest limit of detection and high sensitivity and selectivity. Graphene quantum dots (GQDs) have emerged as a highly potential sensing material to incorporate with the developed sensors due to the advantages of GQDs. Several recent studies showed that GQDs, functionalized GQDs, and their composites were able to enhance the optical detection of metal ions. The aim of this paper is to review the existing, latest, and updated studies on optical sensing applications of GQDs-based materials toward toxic metal ions and future developments of an excellent GQDs-based SPR sensor as an alternative toxic metal ion sensor.


Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4994
Author(s):  
Weitao Li ◽  
Ningjia Jiang ◽  
Bin Wu ◽  
Yuan Liu ◽  
Luoman Zhang ◽  
...  

Biological imaging is an essential means of disease diagnosis. However, semiconductor quantum dots that are used in bioimaging applications comprise toxic metal elements that are nonbiodegradable, causing serious environmental problems. Herein, we developed a novel ecofriendly solvothermal method that uses ethanol as a solvent and doping with chlorine atoms to prepare highly fluorescent graphene quantum dots (GQDs) from seaweed. The GQDs doped with chlorine atoms exhibit high-intensity white fluorescence. Thus, their preliminary application in bioimaging has been confirmed. In addition, clear cell imaging could be performed at an excitation wavelength of 633 nm.


Author(s):  
Igor Araújo Pinto ◽  
Carlos A.T. Toloza ◽  
Joseany M.S. Almeida ◽  
Andrea R. da Silva ◽  
Dunieskys G. Larrude ◽  
...  

2015 ◽  
Vol 51 (20) ◽  
pp. 4176-4179 ◽  
Author(s):  
Yiyang Liu ◽  
Doo Young Kim

UV- and blue-emitting graphene quantum dots (GQDs) were synthesized from carbon nano-onions and compared for metal ion sensing.


2019 ◽  
Vol 2 (11) ◽  
pp. 6858-6865 ◽  
Author(s):  
Zackery S. Schroer ◽  
Yingfen Wu ◽  
Yuqian Xing ◽  
Xu Wu ◽  
Xiao Liu ◽  
...  

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Fei Lu ◽  
Yi-hua Zhou ◽  
Li-hui Wu ◽  
Jun Qian ◽  
Sheng Cao ◽  
...  

Nitrogen-doped graphene quantum dots (N-GQDs) with strong blue fluorescence and a high quantum yield of 88.9% were synthesized via a facile one-pot hydrothermal treatment with citric acid (CA) and ethylenediamine (EDA) as carbon and nitrogen sources, respectively. The blue fluorescence emission is independent of the excitation wavelengths. These N-GQDs dispersed well in water and ethyl alcohol and showed a highly selective and sensitive detection of hazardous and toxic Fe3+in the range of 1600μmol/L to 6000μmol/L through a fluorescence quenching process with a detection limit of 2.37μmol/L. Based on the excellent sensitivity and selectivity of N-GQDs to heavy metal ions, paper-based sensors can be fabricated by inkjet printing, which are rapid but low cost. So the visual instant on-site identification of heavy metal ion will be realized in the future.


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