scholarly journals Facile Synthesis of Surface-Modified Carbon Quantum Dots (CQDs) for Biosensing and Bioimaging

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3313 ◽  
Author(s):  
Łukasz Janus ◽  
Julia Radwan-Pragłowska ◽  
Marek Piątkowski ◽  
Dariusz Bogdał
Keyword(s):  
Quantum Dots ◽  
Chemical Structure ◽  
Water Solubility ◽  
Organic Dyes ◽  
Carbon Quantum Dots ◽  
Raw Material ◽  
The Novel ◽  
Surface Modified ◽  
Synthesis Approach ◽  
Effective Analysis

Recently, fluorescent probes became one of the most efficient tools for biosensing and bioimaging. Special attention is focused on carbon quantum dots (CQDs), which are characterized by the water solubility and lack of cytotoxicity. Moreover, they exhibit higher photostability comparing to traditional organic dyes. Currently, there is a great need for the novel, luminescent nanomaterials with tunable properties enabling fast and effective analysis of the biological samples. In this article, we propose a new, ecofriendly bottom-up synthesis approach for intelligent, surface-modified nanodots preparation using bioproducts as a raw material. Obtained nanomaterials were characterized over their morphology, chemical structure and switchable luminescence. Their possible use as a nanodevice for medicine was investigated. Finally, the products were confirmed to be non-toxic to fibroblasts and capable of cell imaging.

scholarly journals Rapid Synthesis of highly luminescent Carbon Quantum Dots using Low-Pressurized Microwave Solvothermal Heating

2019 ◽  
Author(s):  
Kenta Hagiwara ◽  
Satoshi Horikoshi
Keyword(s):  
Quantum Dots ◽  
Carbon Quantum Dots ◽  
Synthetic Methods ◽  
Quantum Yields ◽  
Protective Agent ◽  
The Novel ◽  
Microwave Chemistry ◽  
High Quantum ◽  
Surface Modified ◽  
The Relationship

Since the first serendipity of carbon quantum dots (CQDs)1, it is expected to be used for imaging materials for reusable living bodies (e.g. Hela cells). However, the reported CQDs synthetic methods have yet to be at the practical levels; the quantum yields is low, and synthetic condition is over 5 hrs under more than 30 atms. In this research, we ameliorated the problems of CQDs synthesis and luminescence (quantum yields) by the novel synthesis protocol using microwave chemistry. Specifically, we synthesized high quantum yields CQDs (61%) by utilizing a microwave chemical synthesis, synthesizing at low pressure condition (lower than 5 atom) and short reaction time (3 hrs). The achievement of this high quantum yields made it clear that the contribution of polyethylene glycol (PEG) shell to CQDs is large. It was confirmed from the DLS and TEM image that the particle size of the synthesized particles was 8 to 13 nm (Fig. 1). On the other hand, the relationship between the polymerization degree of added PEG and the quantum yields to the addition amount is summarized in Table 1. The quantum yields of CQDs without addition of PEG was 16.7 %, while it was improved at 61.1 % when 0.6 g of PEG6000 (Molecular weight: 6000) was added.We succeeded in remarkably improving the quantum yields by using PEG, which is usually used as a protective agent, as a shell. By using this method, we succeeded in improving the quantum yields of the existing report by approximately 3 times. From the surface modified structure of PEG, the mechanism of improvement of quantum yields will be considered.[1] X. Xu et al., J. Am. Chem. Soc., 2004, 126, 12736–12737. 

scholarly journals Coumarin-Modified CQDs for Biomedical Applications—Two-Step Synthesis and Characterization

2020 ◽  
Vol 21 (21) ◽  
pp. 8073 ◽  
Author(s):  
Łukasz Janus ◽  
Julia Radwan-Pragłowska ◽  
Marek Piątkowski ◽  
Dariusz Bogdał
Keyword(s):  
Quantum Dots ◽  
Method Development ◽  
Water Solubility ◽  
Hydrothermal Carbonization ◽  
Carbon Quantum Dots ◽  
Raw Material ◽  
Carbon Nanodots ◽  
Waste Biomass ◽  
Xtt Assay ◽  
Fluorescence Characteristics

Waste biomass such as lignin constitutes a great raw material for eco-friendly carbon quantum dots (CQDs) synthesis, which find numerous applications in various fields of industry and medicine. Carbon nanodots, due to their unique luminescent properties as well as water-solubility and biocompatibility, are superior to traditional organic dyes. Thus, obtainment of CQDs with advanced properties can contribute to modern diagnosis and cell visualization method development. In this article, a new type of coumarin-modified CQD was obtained via a hybrid, two-step pathway consisting of hydrothermal carbonization and microwave-assisted surface modification with coumarin-3-carboxylic acid and 7-(Diethylamino) coumarin-3-carboxylate. The ready products were characterized over their chemical structure and morphology. The nanomaterials were confirmed to have superior fluorescence characteristics and quantum yield up to 18.40%. They also possessed the ability of biomolecules and ion detection due to the fluorescence quenching phenomena. Their lack of cytotoxicity to L929 mouse fibroblasts was confirmed by XTT assay. Moreover, the CQDs were proven over their applicability in real-time bioimaging. Obtained results clearly demonstrated that proposed surface-modified carbon quantum dots may become a powerful tool applicable in nanomedicine and pharmacy.

Hybrid nanostructured C-dot decorated Fe3O4electrode materials for superior electrochemical energy storage performance

2015 ◽  
Vol 44 (19) ◽  
pp. 9221-9229 ◽  
Author(s):  
K. Bhattacharya ◽  
P. Deb
Keyword(s):  
Quantum Dots ◽  
Energy Storage ◽  
Specific Capacitance ◽  
High Specific Capacitance ◽  
Carbon Quantum Dots ◽  
Electrochemical Energy Storage ◽  
The Novel ◽  
Hybrid Nanocomposite ◽  
Storage Performance ◽  
Electrochemical Energy

Here, the novel Fe3O4-C hybrid nanocomposite demonstrates high specific capacitance (S.C.) than the pristine Fe3O4nanospheres due to the presence of the highly conducting carbon quantum dots.

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.

scholarly journals Gamma ray assisted modification of carbon quantum dot/polyurethane nanocomposites: structural, mechanical and photocatalytic study

RSC Advances ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 6278-6286 ◽  
Author(s):  
Milica Budimir ◽  
Zoran Marković ◽  
Dragana Jovanović ◽  
Miloš Vujisić ◽  
Matej Mičušík ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Quantum Dot ◽  
Photocatalytic Degradation ◽  
Gamma Ray ◽  
Organic Dyes ◽  
Carbon Quantum Dots ◽  
Carbon Quantum Dot ◽  
Polyurethane Nanocomposites

The present study reports the results of the gamma ray-assisted modification of hydrophobic carbon quantum dots (hCQDs)/polyurethane nanocomposites for photocatalytic degradation of organic dyes.

Tandem structured luminescent solar concentrator based on inorganic carbon quantum dots and organic dyes

Solar Energy ◽  
2019 ◽  
Vol 190 ◽  
pp. 488-494 ◽  
Author(s):  
Fahad Mateen ◽  
Mumtaz Ali ◽  
Sae Youn Lee ◽  
Sung Hoon Jeong ◽  
Min Jae Ko ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Inorganic Carbon ◽  
Organic Dyes ◽  
Carbon Quantum Dots ◽  
Solar Concentrator ◽  
Luminescent Solar Concentrator

Synthesis of carbon quantum dot-surface modified P25 nanocomposites for photocatalytic degradation of p-nitrophenol and acid violet 43

RSC Advances ◽  
2014 ◽  
Vol 4 (58) ◽  
pp. 30605-30609 ◽  
Author(s):  
Fengying Zheng ◽  
Zhenhua Wang ◽  
Jie Chen ◽  
ShunXing Li
Keyword(s):  
Quantum Dots ◽  
Water Treatment ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Carbon Quantum Dots ◽  
Chemical Adsorption ◽  
Carbon Quantum Dot ◽  
Visible Light Driven ◽  
Surface Modified ◽  
Acid Violet

A new efficient and stable visible light driven photocatalyst, carbon quantum dots (CQDs)-surface modified P25 nanocomposite, was successfully prepared by chemical adsorption of CQDs onto the surface of TiO2 nanoparticles and then used for water treatment.

scholarly journals An Alternative Route to Obtain Carbon Quantum Dots from Photoluminescent Materials in Peat

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1492 ◽  
Author(s):  
Rafael Souza da Costa ◽  
Wiliam Ferreira da Cunha ◽  
Nizamara Simenremis Pereira ◽  
Artemis Marti Ceschin
Keyword(s):  
Quantum Dots ◽  
Aromatic Compounds ◽  
Elemental Carbon ◽  
Low Cost ◽  
Carbon Quantum Dots ◽  
Raw Material ◽  
Transmission Electron ◽  
Photoluminescent Materials ◽  
Average Size ◽  
Green Coloration

Peat, an organic compound easily found in the soil (easy to acquire), has more than 50% elemental carbon in its composition and can be used as raw material to produce carbon quantum dots (CQDs, C-dots, Carbon Dots). In this work we describe two simple and low-cost routes for the acquisition of these photoluminescent materials based on peat. The final products were characterized by Fourier transform infrared spectroscopy (FTIR), absorption (UV-Vis) and emission (PL) spectra and high-resolution transmission electron microscopy (HRTEM). The produced CQDs have an average size of 3.5 nm and exhibit coloration between blue and green. In addition, it is possible to produce photoluminescence by means of the aromatic compounds also present in the composition of the peat, in turn exhibiting an intense green coloration. The results indicate great versatility of peat for the production of photoluminescent materials.

scholarly journals Polyethylene Glycol6000/carbon Nanodots as Fluorescent Bioimaging Agents

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 677 ◽  
Author(s):  
Chun-Chieh Fu ◽  
Chun-Yung Wu ◽  
Chih-Ching Chien ◽  
Tai-Hao Hsu ◽  
Shih-Fu Ou ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Carbon Quantum Dots ◽  
Carbon Nanodots ◽  
Gram Negative Bacteria ◽  
Fluorescent Properties ◽  
Gram Positive ◽  
Gram Negative ◽  
Different Types ◽  
Living Organisms ◽  
Surface Modified

Photoluminescent nanomaterials have immense potential for use in biological systems due to their excellent fluorescent properties and small size. Traditional semiconductor quantum dots are heavy-metal-based and can be highly toxic to living organisms, besides their poor photostability and low biocompatibility. Nano-sized carbon quantum dots and their surface-modified counterparts have shown improved characteristics for imaging purposes. We used 1,3, 6-trinitropyrene (TNP) and polyethylene glycol6000 (PEG6000) in a hydrothermal method to prepare functional polyethylene glycol6000/carbon nanodots (PEG6000/CDs) and analyzed their potential in fluorescent staining of different types of bacteria. Our results demonstrated that PEG6000/CDs stained the cell pole and septa of gram-positive bacteria B. Subtilis and B. thuringiensis but not those of gram-negative bacteria. The optimal concentration of these composite nanodots was approximately 100 ppm and exposure times varied across different bacteria. The PEG6000/CD composite had better photostability and higher resistance to photobleaching than the commercially available FM4-64. They could emit two wavelengths (red and green) when exposed to two different wavelengths. Therefore, they may be applicable as bioimaging molecules. They can also be used for differentiating different types of bacteria owing to their ability to differentially stain gram-positive and gram-negative bacteria.

Green Synthetic Fluorescent Carbon Quantum Dot as pH Sensor Applied to Real Water Samples Determination

NANO ◽  
2021 ◽  
pp. 2150093
Author(s):  
Yong Zhang ◽  
Sijie Cheng ◽  
Yanteng Xiao ◽  
Yingte Wang
Keyword(s):  
Water Samples ◽  
Water Solubility ◽  
Ph Sensor ◽  
Blue Emission ◽  
Carbon Quantum Dots ◽  
Raw Material ◽  
Narrow Particle Size Distribution ◽  
Ph Response ◽  
Real Water Samples ◽  
One Step

Willow, a common tree species, is mainly distributed in temperate regions of the Northern Hemisphere. Catkins are the seeds of willow. In addition to propagating new willows, it is of great significance to study its application in other areas. Carbon quantum dots (CQDs) have attracted extensive attention owing to their excellent luminescence properties, low toxicity and water solubility. The use of CQDs for accurate measurement of pH is of great significance in environmental, medical and other fields. Based on this, blue-emission fluorescent CQDs with 4.93% quantum yield (Q.Y.) are prepared via natural product catkins as the only raw material by one-step hydrothermal method. The prepared CQDs exhibit excellent water solubility, narrow particle size distribution, excitation-dependent photoluminescence properties and sensitive pH response behavior. The fluorescence intensity of CQDs has a good linear relationship with pH in the range of 6–12, and the correlation coefficient is 0.994. In addition, the CQDs have good stability, and the response to pH displays excellent reversibility, which can be developed as a pH sensor to quantitatively monitor the pH values in real water samples. Thereby, the potential practical application is promising.

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