Synthesis, Photoluminescence and Bio-Targeting Applications of Blue Graphene Quantum Dots

2016 ◽  
Vol 16 (4) ◽  
pp. 3457-3467 ◽  
Author(s):  
Jigang Wang ◽  
Ji Zhou ◽  
Wenhua Zhou ◽  
Jilong Shi ◽  
Lun Ma ◽  
...  

Chemical derived graphene oxide, an atomically thin sheet of graphite with two-dimensional construction, offers interesting physical, electronic, thermal, chemical, and mechanical properties that are currently being explored for advanced physics electronics, membranes, and composites. Herein, we study graphene quantum dots (GQD) with the blue photoluminescence under various parameters. The GQD samples were prepared at different temperatures, and the blue photoluminescence intensity of the solution improved radically as the heating temperatures increased. Concerning PL peak and intensity of the quantum dots, the results demonstrated dependence on time under heating, temperature of heating, and pH adjusted by the addition of sodium hydroxide. After hydrothermal synthesis routes, the functional groups of graphene oxide were altered the morphology showed the stacking configuration, and self-assembled structure of the graphene sheets with obvious wrinkles appeared at the edge structures. In addition, absorption, PL, and PLE spectra of the graphene quantum dots increase with different quantities of sodium hydroxide added. Finally, using GQD to target PNTIA cells was carried out successfully. High uptake efficiency and no cytotoxic effects indicate graphene quantum dots can be suitable for bio-targeting.

2014 ◽  
Vol 950 ◽  
pp. 44-47 ◽  
Author(s):  
Hui Li ◽  
Hai Ping He ◽  
Zhi Zhen Ye

Highly bright-fluorescent N (nitrogen), S (sulfur) co-doped graphene quantum dots (GQDs) were synthesized through an modified hydrothermal method. The doped GQDs are smaller than 10 nm in size in average and stable in aqueous solution. Unlike many reports on graphene oxide (GO), the as-synthesized doped GQDs exhibit bright blue photoluminescence (PL) emission and the emission wavelength is excitation-independent. The intriguling results indicate that GQDs may have great potential in the optic and optoelectronic applications.


2021 ◽  
Author(s):  
Xu Dan ◽  
Ruiyi Li ◽  
Qinsheng Wang ◽  
Yongqiang Yang ◽  
Haiyan Zhu ◽  
...  

The paper reports the synthesis of nickel-silver-graphene quantum dot-graphene hybrid. Histidine-functionalized graphene quantum dots (His-GQDs) were bonded to graphene oxide (GO) and then combined with Ni2+ and Ag+ to form...


2021 ◽  
Vol 73 ◽  
pp. 105519
Author(s):  
Yuxin Yan ◽  
Sivakumar Manickam ◽  
Edward Lester ◽  
Tao Wu ◽  
Cheng Heng Pang

Author(s):  
Ruibin Qiang ◽  
Weiming Sun ◽  
Kaiming Hou ◽  
Zhangpeng Li ◽  
Jinyun Zhang ◽  
...  

ACS Omega ◽  
2017 ◽  
Vol 2 (10) ◽  
pp. 7293-7298 ◽  
Author(s):  
Jiali Zhang ◽  
Fangwei Zhang ◽  
Yaoyao Yang ◽  
Shouwu Guo ◽  
Jingyan Zhang

2016 ◽  
Vol 40 (11) ◽  
pp. 9111-9124 ◽  
Author(s):  
A. Muthurasu ◽  
P. Dhandapani ◽  
V. Ganesh

A simple and facile method for the simultaneous preparation of graphene quantum dots (GQDs) having different emission colours, viz., yellow, green and blue, and reduced graphene oxide (RGO) utilized respectively for bio-imaging and supercapacitor applications is demonstrated.


2017 ◽  
Vol 5 (31) ◽  
pp. 6300-6306 ◽  
Author(s):  
Lin Cao ◽  
Xiangqing Li ◽  
Lixia Qin ◽  
Shi-Zhao Kang ◽  
Guodong Li

A new class of Cyt c detection fluorescence sensor based on graphene quantum dots supported by graphene oxide has been facilely developed. The sensor shows a high sensitivity and selectivity for Cyt c detection, and further exhibits favorable intracellular imaging in A549 cells.


2014 ◽  
Vol 922 ◽  
pp. 469-474 ◽  
Author(s):  
Sho Manabe ◽  
Hiroshi Utsunomiya ◽  
Tetsuo Sakai ◽  
Ryo Matsumoto

Magnesium alloys show low deformability at low temperature because of hcp structure and inactiveness of basal slip. Manufacturing of thin sheet is difficult in industries. Some approaches, such as small-draft multi-pass rolling, intermediate annealing, isothermal rolling and high-speed rolling were proposed to overcome the deformability. However, small edge cracks are still formed on the sheet. In this study, rolling speed of 1000m/min was employed to warm-roll AZ31B magnesium alloy in a single pass at different temperatures. The edge cracks formed after the rolling were classified into three main groups: minor, regular and zigzag edge cracks. ‘Crack contact length’ are introduced to explain the morphology of edge cracks. The results show that the critical reduction for crack initiation depends on the pre-heating temperature. The spacing between edge cracks increases linearly with the crack contact length regardless of roll diameter, speed and reduction. It is suggested that this approach is useful to understand the formation mechanism of edge cracks and to evaluate the rollability of magnesium alloys.


Nanomaterials ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 104 ◽  
Author(s):  
Rabeb El-Hnayn ◽  
Laetitia Canabady-Rochelle ◽  
Christophe Desmarets ◽  
Lavinia Balan ◽  
Hervé Rinnert ◽  
...  

2,2’-(Ethylenedioxy)bis(ethylamine)-functionalized graphene quantum dots (GQDs) were prepared under mild conditions from graphene oxide (GO) via oxidative fragmentation. The as-prepared GQDs have an average diameter of ca. 4 nm, possess good colloidal stability, and emit strong green-yellow light with a photoluminescence (PL) quantum yield of 22% upon excitation at 375 nm. We also demonstrated that the GQDs exhibit high photostability and the PL intensity is poorly affected while tuning the pH from 1 to 8. Finally, GQDs can be used to chelate Fe(II) and Cu(II) cations, scavenge radicals, and reduce Fe(III) into Fe(II). These chelating and reducing properties that associate to the low cytotoxicity of GQDs show that these nanoparticles are of high interest as antioxidants for health applications.


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