Development of steady-state electrical-heating fluorescence-sensing (SEF) technique for thermal characterization of one dimensional (1D) structures by employing graphene quantum dots (GQDs) as temperature sensors

2016 ◽  
Vol 27 (44) ◽  
pp. 445706 ◽  
Author(s):  
Xiang Wan ◽  
Changzheng Li ◽  
Yanan Yue ◽  
Danmei Xie ◽  
Meixin Xue ◽  
...  
2021 ◽  
Author(s):  
Md. Farhan Naseh ◽  
Neelam Singh ◽  
Jamilur R. Ansari ◽  
Ashavani Kumar ◽  
Tapan Sarkar ◽  
...  

Abstract Here, we report functionalized graphene quantum dots (GQDs) for the optical detection of arsenic at room temperature. GQDs with the fluorescence of three fundamental colors (red, green, and blue) were synthesized and functionally capped with L-cysteine (L-cys) to impart selectively towards As (III) by exploiting the affinity of L-cys towards arsenite. The optical characterization of GQDs was carried out using UV-Vis absorption spectroscopy, Fourier transform infrared spectroscopy, and fluorescence spectrometry and the structural characterizations were performed using transmission electron microscopy. The fluorescence results showed instantaneous quenching in intensity when the GQDs came in contact with As (III) for all test concentrations over a range from 0.025 ppb to 25 ppb, which covers the permissible limit of arsenic in drinking water. The experimental results suggested excellent sensitivity and selectivity towards As (III).


2021 ◽  
Author(s):  
Bingyang Li ◽  
Xiao Xiao ◽  
Menglei Hu ◽  
Yanxin Wang ◽  
Yiheng Wang ◽  
...  

Author(s):  
Shilpa Ramachandran ◽  
M. Sathishkumar ◽  
Nikhil K. Kothurkar ◽  
R. Senthilkumar

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Lam Minh Long ◽  
Nguyen Nang Dinh ◽  
Tran Quang Trung

Graphene quantum dots (GQDs) were synthesized and incorporated with polyethylenedioxythiophene:poly(4-styrenesulfonate) (PEDOT:PSS) and carbon nanotube (CNT) to form a composite that can be used for humidity sensors. The 600 nm thick composite films contained bulk heterojunctions of CNT/GQD and CNT/PEDOT:PSS. The sensors made from the composites responded well to humidity in a range from 60 to 80% at room temperature and atmospheric pressure. With a CNT content of 0.4 wt.% (GPC-1) to 0.8 wt.% (GPC-2) and 1.2 wt.% (GPC-3), the sensitivity of the humidity sensing devices based on CNT-doped graphene quantum dot-PEDOT:PSS composites was increased from 4.5% (GPC-1) to 9.0% (GPC-1) and 11.0% (GPC-2), respectively. The fast response time of the GPC sensors was about 20 s and it was much improved due to CNTs doping in the composites. The best value of the recovery time was found to be of 40 s, for the GPC composite film doped with 1.2 wt.% CNT content.


2018 ◽  
Vol 10 (15) ◽  
pp. 1760-1766 ◽  
Author(s):  
Fatemeh Nemati ◽  
Morteza Hosseini ◽  
Rouholah Zare-Dorabei ◽  
Mohammad Reza Ganjali

To achieve a fast, sensitive and inexpensive method for the detection of ethion in the presence of Hg2+ ions, a nitrogen and sulfur co-doped graphene quantum dot (N,S/GQD)-based fluorescence sensing system was developed.


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