Microwave-assisted synthesis of carbon dots and their applications

2019 ◽  
Vol 7 (24) ◽  
pp. 7175-7195 ◽  
Author(s):  
Tayline V. de Medeiros ◽  
John Manioudakis ◽  
Farah Noun ◽  
Jun-Ray Macairan ◽  
Florence Victoria ◽  
...  
Keyword(s):  
Optical Properties ◽  
Carbon Dots ◽  
Microwave Assisted Synthesis ◽  
Carbon Allotrope ◽  
Microwave Assisted ◽  
Physico Chemical ◽  
Significant Attention

Carbon dots, an emerging class within the carbon allotrope family, have gained significant attention largely due to their versatile and tunable physico-chemical and optical properties.

scholarly journals Microwave Assisted Synthesis and Optical Properties of Highly Fluorescent N-Doped Carbon Dots

2019 ◽  
Vol 31 (12) ◽  
pp. 2897-2902
Author(s):  
D. Koteswararao ◽  
B. Rajkumar ◽  
K. Prameela ◽  
K. Ashok ◽  
G. Sridevi
Keyword(s):  
Optical Properties ◽  
Carbon Dots ◽  
Irradiation Time ◽  
Guanidine Hydrochloride ◽  
Fluorescence Emission ◽  
Microwave Assisted Synthesis ◽  
Solid State Method ◽  
Microwave Assisted ◽  
Wide Range ◽  
Doped Carbon Dots

Herein, a rapid microwave assisted solid state method is reported for the synthesis of highly fluorescent N-doped carbon dots (NCDs) using citric acid as carbon source and guanidine hydrochloride as N-dopant. Synthetic parameters such as microwave power, irradiation time and reactants ratio were optimized to produce high quality N-doped carbon dots. The N-doped carbon dots were well characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), SEM-EDS, FTIR, UV-visible and fluorescence spectroscopies. N-Doped carbon dots exhibited bright emission with a quantum yield of 11 %. Detailed study of their optical properties revealed their excellent property of resistance to photo bleaching, high ionic strength and solution pH. Further they exhibited excitation dependent emission behaviour, high aqueous solubility and a long shelf life of 60 days. This strong fluorescence emission combined with high stability make N-doped carbon dots a promising fluorescent probe for wide range of applications.

Size-Controlled Microwave-Assisted Synthesis of Water-Dispersible Cd(Se,S) Quantum Dots for Potential Biological Applications

2015 ◽  
Vol 1784 ◽  
Author(s):  
E. Calderón-Ortiz ◽  
S. Bailón-Ruiz ◽  
L. Alamo-Nole ◽  
J. Rodriguez-Orengo ◽  
O. Perales-Perez
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Quantum Confinement Effect ◽  
Reactive Oxygen Species Generation ◽  
Size Control ◽  
Average Crystallite Size ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted

ABSTRACTNanomedicine is fostering significant advances in the development of platforms for early detection and treatment of diseases. Nanoparticles (NPs) like quantum dots (QDs) exhibit size-dependent optical properties for light-driven technologies, which might become important in bio-imaging, sensing and photo-dynamic therapy (PDT) applications. The present research addresses the synthesis of water-stable Cd-based QDs via a Microwave-Assisted synthesis approach using cadmium sulfate salt, and thioglycolic acid as Cd- and S-precursors, respectively. Selenide ions were available by reductive leaching of metallic Selenium in Sodium bisulfite solution. The size control and the tunability of the optical properties were achieved by a suitable control of the reaction temperature (in the 140°C- 190°C range) and reaction time (10 minutes-40 minutes). X-ray diffraction analyses suggested the development of a CdSe,S face cubic centered structure; the broadening of the diffraction peaks indicated the presence of very small nanocrystals in the samples. The average crystallite size was estimated at 5.50 nm ± 1.17nm and 3.72 nm ± 0.04 nm, for nanoparticles synthesized at 180°C after 40 minutes or 10 minutes of reaction, respectively. HRTEM images confirmed the crystalline nature and the small size of the synthesized nanocrystals. In turn, the exciton was red-shifted from 461nm to 549 nm when the reaction temperature was prolonged from 140°C to 190 °C, suggesting the crystal growth. The corresponding band gap values were approximately 2.2 eV, confirming the quantum confinement effect (bulk value 1.74eV). This red shift was also evidenced in PL measurements where the main emission peak was shifted from 507 nm to 564 nm when the samples were excited at 420 nm. A narrow size-tunable emission also was supported by the full width at half maximum (∼ 45 nm) for the synthesized nanocrystals. The reactive oxygen species generation capability of as-synthesized QDs was also investigated. The correlation between the particle size and the generation of (ROS) by the degradation of methylene blue was evident with a reduction of MB concentration from 10μM to 7.5μM and 6.7μM after 15 minutes of UV irradiation for reaction time of 10 min. and 40 min. respectively. No additional degradation was noticed after 60 minutes of irradiation.

Microwave-assisted synthesis of nitrogen doped carbon dots using prickly pear as the carbon source and its application as highly selective sensor for Cr(VI) and as patterning agent

2021 ◽  
Author(s):  
Shreya Bhatt ◽  
Gaurav Vyas ◽  
Parimal Paul
Keyword(s):  
Carbon Dots ◽  
Microwave Assisted Synthesis ◽  
Nitrogen Doped ◽  
Water Dispersible ◽  
Microwave Assisted ◽  
Bio Imaging ◽  
Natural Carbon ◽  
Doped Carbon Dots ◽  
Nitrogen Doped Carbon ◽  
Selective Sensor

Preparation of water dispersible carbon dots from inexpensive natural carbon precursors and its application for purposes such as sensing, bio-imaging, patterning agent etc. is showing growing interest in recent years....

Microwave-assisted synthesis of carbon dots–zinc oxide/multi-walled carbon nanotubes and their application in electrochemical sensors for the simultaneous determination of hydroquinone and catechol

RSC Advances ◽  
2016 ◽  
Vol 6 (116) ◽  
pp. 115317-115325 ◽  
Author(s):  
Yaru Yan ◽  
Qitong Huang ◽  
Chan Wei ◽  
Shirong Hu ◽  
Hanqiang Zhang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Zinc Oxide ◽  
Cyclic Voltammetry ◽  
Carbon Dots ◽  
Electrochemical Sensors ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Cyclic voltammetry of HQ and CC recorded on Nafion/CDs–ZnO/MWCNTs/GCE.

Microwave-assisted synthesis of nitrogen-rich carbon dots as effective fluorescent probes for sensitive detection of Ag+

2019 ◽  
Vol 3 (12) ◽  
pp. 2751-2758 ◽  
Author(s):  
Jie Feng ◽  
Xiaoran Zhao ◽  
Wei Bian ◽  
Xinjing Tang
Keyword(s):  
Fluorescent Probes ◽  
Carbon Dots ◽  
Static Quenching ◽  
Sensitive Detection ◽  
Microwave Assisted Synthesis ◽  
Quenching Effect ◽  
Microwave Assisted

Highly fluorescent N-dots are rationally designed and synthesized through microwave-assisted reaction of 2-azidoimidazole with glycerol crosslinker and are employed as an effective chemosensor for Ag+ analysis via the static quenching effect.

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