scholarly journals Synthesis of Sulfur-Selenium Doped Carbon Quantum Dots for Biological Imaging and Scavenging Reactive Oxygen Species

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Guojie Huang ◽  
Yaqi Lin ◽  
Linxiu Zhang ◽  
Zhihong Yan ◽  
Yudong Wang ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Quantum Dots ◽  
Survival Rate ◽  
Photoelectron Spectroscopy ◽  
Reactive Oxygen ◽  
Carbon Quantum Dots ◽  
Hatching Rate ◽  
Oxygen Species ◽  
Transmission Electron ◽  
High Fluorescence

AbstractThe sulfur-selenium doped carbon quantum dots (S,Se-CQDs) were synthesized by one-step through hydrothermal method in this study, which have high fluorescence quantum yield (43%) and advanced ability to scavenge reactive oxygen species (ROS). They were characterized by transmission electron microscope (TEM), nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS), fourier transform infrared spectroscopy (FTIR). The results showed that the clearance rate of free radical reached to 40% with 200 μg/mL of S,Se-CQDs. The antioxidant activity of S,Se-CQDs is related to -SH and Se-SH on carbon quantum dots. S,Se-CQDs were able to access to cells which is beneficial to enhance the removal efficiency to ROS. In the biocompatibility experiment, the cell survival rate exceeded 95%, there was little effect on hatching rate, survival rate and heart rate of zebrafish which demonstrated that S,Se-CQDs have an excellent biocompatibility. It prompts that S,Se-CQDs will has proud application prospects in the field of biomedicine.

scholarly journals The Application of Green-Synthesis-Derived Carbon Quantum Dots to Bioimaging and the Analysis of Mercury(II)

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Qianchun Zhang ◽  
Xiaolan Zhang ◽  
Linchun Bao ◽  
Yun Wu ◽  
Li Jiang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Hela Cells ◽  
Photoelectron Spectroscopy ◽  
Water Solubility ◽  
Limit Of Detection ◽  
Carbon Quantum Dots ◽  
Coefficient Of Determination ◽  
Serum Samples ◽  
X Ray ◽  
Transmission Electron

Ginkgo leaves were used as precursors for the hydrothermal synthesis of carbon quantum dots (CQDs), which were subsequently characterized by transmission electron microscopy as well as Fourier-transform infrared, X-ray powder diffraction, and X-ray photoelectron spectroscopy. The prepared CQDs exhibited a fluorescence quantum yield of 11% and superior water solubility and fluorescence stability, as well as low cytotoxicities and excellent biocompatibilities with A549 and HeLa cells; these CQDs were also used to bioimage HeLa cells. Moreover, owing to the experimental observation that Hg2+ quenches the fluorescence of the CQDs in a specific and sensitive manner, we developed a method for the detection of Hg2+ using this fluorescence sensor. The sensor exhibited a linear range for Hg2+ of 0.50–20 μM, with an excellent coefficient of determination (R2 = 0.9966) and limit of detection (12.4 nM). In practice, the proposed method was shown to be highly selective and sensitive for the monitoring of Hg2+ in lake water and serum samples.

THE ROLES OF PHOTOLUMINESCENT QUANTUM DOTS IN GENERATION OR DETECTION OF REACTIVE OXYGEN SPECIES: CULPRITS OR DETECTIVES?

COSMOS ◽  
2010 ◽  
Vol 06 (02) ◽  
pp. 149-158
Author(s):  
SUHUA WANG ◽  
DEJIAN HUANG
Keyword(s):  
Reactive Oxygen Species ◽  
Quantum Dots ◽  
Organic Dyes ◽  
Resonance Energy Transfer ◽  
Reactive Oxygen ◽  
Resonance Energy ◽  
Oxygen Species ◽  
Positive Side ◽  
Biological Importance ◽  
Organic Sensitizers

In this review, we systematically analyzed the complicated interrelationship between photoluminescent quantum dots (QDs) and reactive oxygen species of biological importance. QDs, when photoexcited, generate reactive oxygen species (ROS), which are partially blamed for the cytotoxicity of QDs. On the positive side, the ability of generating ROS by QDs are exploited in photodynamic therapy using QDs alone or in combination with QD-surface bound organic sensitizers via resonance energy transfer from QDs to the organic dyes. Lastly, depending on the chemical composition and the functionalization of the QDs, ROS are known to quench or switch-on the QD photoluminescence. The selectivity and sensitivity toward specific ROS can be achieved through judicious chemical modification of QD surface coating layers by taking into account the reactivity difference among different ROS. The flexible QD surface functionalization opens up the unprecedented possibility of designer-made nanoprobes for sensing and quantifying ROS of biological importance.

Clean photoinduced generation of free reactive oxygen species by silica films embedded with CdTe–MTA quantum dots

RSC Advances ◽  
2016 ◽  
Vol 6 (11) ◽  
pp. 8563-8571 ◽  
Author(s):  
Gustavo C. S. de Souza ◽  
David S. M. Ribeiro ◽  
S. Sofia M. Rodrigues ◽  
Ana Paula S. Paim ◽  
André F. Lavorante ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Quantum Dots ◽  
Sol Gel ◽  
Reactive Oxygen ◽  
Analytical Application ◽  
Oxygen Species ◽  
Silica Films ◽  
Environment Friendly ◽  
Gel Technique

QDs immobilized into silica films were obtained by sol–gel technique using TMOS. These nanomaterials kept their native PL and the ability to generate ROS opening perspectives for the development of more environment friendly analytical application.

Coenzyme Q Functionalized CdTe/ZnS Quantum Dots for Reactive Oxygen Species (ROS) Imaging

2011 ◽  
Vol 17 (19) ◽  
pp. 5262-5271 ◽  
Author(s):  
Li‐Xia Qin ◽  
Wei Ma ◽  
Da‐Wei Li ◽  
Yang Li ◽  
Xiaoyuan Chen ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Quantum Dots ◽  
Coenzyme Q ◽  
Reactive Oxygen ◽  
Oxygen Species

Graphene Oxide Quantum Dots-Induced Mineralization via the Reactive Oxygen Species-Dependent Autophagy Pathway in Dental Pulp Stem Cells

2020 ◽  
Vol 16 (6) ◽  
pp. 965-974
Author(s):  
Xincong Li ◽  
Hanxiao Liu ◽  
Yijun Yu ◽  
Lan Ma ◽  
Chao Liu ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Stem Cells ◽  
Quantum Dots ◽  
Graphene Oxide ◽  
Reactive Oxygen ◽  
Stem Cell Differentiation ◽  
Oxygen Species ◽  
Odontoblastic Differentiation ◽  
Autophagic Activity ◽  
Graphene Oxide Quantum Dots

As an important recycling and degradation system, autophagy is considered to be critical in regulating stem cell differentiation. It has been shown that graphene oxide quantum dots (GOQDs) are a robust biological labelling tool for stem cells with little cytotoxicity. In this study, we explored the role of autophagy in regulating the impact of GOQDs on the odontoblastic differentiation of DPSCs during autophagy. Western blotting and immunofluorescence staining were used to evaluate the autophagic activity of DPSCs. Quantitative PCR, alizarin red S staining, and alkaline phosphatase staining were used to examine DPSC odontoblastic differentiation. The impacts of ROS scavengers on autophagy induction and reactive oxygen species (ROS) levels were also measured. Lentiviral vectors carrying Beclin1 siRNA sequences, as well as autophagy inhibitors (3-MA and bafilomycin A1), were used to inhibit autophagy. Initial exposure to GOQDs increased autophagic activity and enhanced DPSC mineralization. Autophagy inhibition suppressed GOQD-induced odontoblastic differentiation. Moreover, GOQD treatment induced autophagy in a ROS-dependent manner. GOQDs promoted differentiation, which could be modulated via ROS-induced autophagy.

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