scholarly journals Surface Density of Charged Functional Groups on Quantum Dots Determines Their Intracellular Compartmentalization and Biocompatibility

2017 ◽  
Vol 1 (1) ◽  
Author(s):  
Williams Yvonne ◽  
Sukhanova Alyona ◽  
Conroy Jennifer ◽  
Mohamed Bashir ◽  
Oleinikov Vladimir ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Functional Groups ◽  
Surface Density ◽  
Intracellular Compartmentalization

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.

scholarly journals Cellular distribution and cytotoxicity of graphene quantum dots with different functional groups

2014 ◽  
Vol 9 (1) ◽  
pp. 108 ◽  
Author(s):  
Xiaochan Yuan ◽  
Zhiming Liu ◽  
Zhouyi Guo ◽  
Yanhong Ji ◽  
Mei Jin ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Functional Groups ◽  
Graphene Quantum Dots ◽  
Cellular Distribution

Origin of green luminescence in carbon quantum dots: specific emission bands originate from oxidized carbon groups

2018 ◽  
Vol 42 (6) ◽  
pp. 4603-4611 ◽  
Author(s):  
Zhiguo Sun ◽  
Xiaoming Li ◽  
Ye Wu ◽  
Changting Wei ◽  
Haibo Zeng
Keyword(s):  
Quantum Dots ◽  
Functional Groups ◽  
Surface State ◽  
Carbon Quantum Dots ◽  
Green Luminescence ◽  
Oxidized Carbon

This study demonstrates that the surface state functional groups are responsible for green waveband originating from CDs.

scholarly journals Biodistribution and acute toxicity of cadmium-free quantum dots with different surface functional groups in mice following intratracheal inhalation

2020 ◽  
Vol 4 (3) ◽  
pp. 173-183
Author(s):  
Guimiao Lin ◽  
Ting Chen ◽  
Yongning Pan ◽  
Zhiwen Yang ◽  
Li Li ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Acute Toxicity ◽  
Functional Groups ◽  
Surface Functional Groups

Multisensing Capability of MoSe2 Quantum Dots by Tuning Surface Functional Groups

2018 ◽  
Vol 1 (7) ◽  
pp. 3453-3463 ◽  
Author(s):  
Namasivayam Dhenadhayalan ◽  
Ta-Wei Lin ◽  
Hsin-Lung Lee ◽  
King-Chuen Lin
Keyword(s):  
Quantum Dots ◽  
Functional Groups ◽  
Surface Functional Groups

How functional groups influence the ROS generation and cytotoxicity of graphene quantum dots

2017 ◽  
Vol 53 (76) ◽  
pp. 10588-10591 ◽  
Author(s):  
Ya Zhou ◽  
Hanjun Sun ◽  
Faming Wang ◽  
Jinsong Ren ◽  
Xiaogang Qu
Keyword(s):  
Quantum Dots ◽  
Functional Groups ◽  
Graphene Quantum Dots ◽  
Ros Generation ◽  
Hydroxyl Groups ◽  
Carbonyl Groups ◽  
Oxygen Functional Groups

Herein we selectively deactivate the ketonic carbonyl, carboxylic, or hydroxyl groups on GQDs and compare their ROS generation ability. The ROS generation ability of GQDs is closely related to these oxygen functional groups, especially for the ketonic carbonyl groups.

Selective engineering of oxygen-containing functional groups using the alkyl ligand oleylamine for revealing the luminescence mechanism of graphene oxide quantum dots

Nanoscale ◽  
2017 ◽  
Vol 9 (47) ◽  
pp. 18635-18643 ◽  
Author(s):  
Min-Ho Jang ◽  
Hyunseung Yang ◽  
Yun Hee Chang ◽  
Hyun-Chul Park ◽  
Hyeonjung Park ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Graphene Oxide ◽  
Functional Groups ◽  
Light Emission ◽  
Epoxide Group ◽  
Graphene Oxide Quantum Dots

The role of the epoxide group in light emission of GOQDs is demonstrated by selective passivation using the alkyl ligand oleylamine.

scholarly journals Independent Control Over Size and Surface Density of Droplet Epitaxial Nanostructures Using Ultra-Low Arsenic Fluxes

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1184
Author(s):  
Sergey V. Balakirev ◽  
Natalia E. Chernenko ◽  
Mikhail M. Eremenko ◽  
Oleg A. Ageev ◽  
Maxim S. Solodovnik
Keyword(s):  
Quantum Dots ◽  
Surface Density ◽  
Growth Conditions ◽  
Droplet Epitaxy ◽  
Droplet Volume ◽  
Initial Size ◽  
Group V ◽  
New Approach ◽  
Precise Control ◽  
Deposition Amount

Modern and future nanoelectronic and nanophotonic applications require precise control of the size, shape and density of III-V quantum dots in order to predefine the characteristics of devices based on them. In this paper, we propose a new approach to control the size of nanostructures formed by droplet epitaxy. We reveal that it is possible to reduce the droplet volume independently of the growth temperature and deposition amount by exposing droplets to ultra-low group-V flux. We carry out a thorough study of the effect of arsenic pressure on the droplet characteristics and demonstrate that indium droplets with a large initial size (>100 nm) and a low surface density (<108 cm−2) are able to shrink to dimensions appropriate for quantum dot applications. Small droplets are found to be unstable and difficult to control, while larger droplets are more resistive to arsenic flux and can be reduced to stable, small-sized nanostructures (~30 nm). We demonstrate the growth conditions under which droplets transform into dots, ring and holes and describe a mechanism of this transformation depending on the ultra-low arsenic flux. Thus, we observe phenomena which significantly expand the capabilities of droplet epitaxy.

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