scholarly journals Preparation of water-soluble asphalt carbon dots and hyperchromic effect to Cr (VI)

2018 ◽  
Vol 238 ◽  
pp. 02007
Author(s):  
Lijuan Gao ◽  
Jia Sui ◽  
Xiaoqin Qiao ◽  
Chaoshuai Hu ◽  
Xuefei Zhao
Keyword(s):  
Carbon Dots ◽  
Water Solubility ◽  
Fluorescence Emission ◽  
Acid Precipitation ◽  
Water Soluble ◽  
Raw Material ◽  
Precipitation Method ◽  
Acid Oxidation ◽  
Excitation Wavelength ◽  
Uv Spectrum

Water-soluble asphalt carbon dots (W-CDs) was prepared from medium - temperature coal tar pitch as raw material, via mixed acid oxidation, alkali solubilization and acid precipitation method. It was observed that as-prepared W-CDs were irregular particles with good water dispersibility and the particle size was controlled by the pH of the acid precipitation solution by a polarizing microscope. Infrared spectroscopy confirmed that the surface of the W-CDs was functionalized by hydrophilic and color-promoting functional groups, which had good water solubility; the thermal weight loss proved to be good thermal stability below 200°C; the fluorescence spectrum proved that the fluorescence emission peak position of the carbon dots appears red shift with increase of excitation wavelength, with fluorescence conversion property, and its emission light intensity decreases, belonging to non-resonant fluorescence type of direct jump fluorescence; UV spectrum proves that the addition of W-CDs can be chromium (VI) CrO42- content The detection limit was increased from milligram to microgram; the molar absorptivity of CrO42- was increased by 4 times. The experimentally optimized W-CDs-ultraviolet-viscometry method for measuring CrO42- conditions: W-CDs to chromium ratio of 8:2, pH of 8, hexamethylenetetramine as a surfactant, and the solution was allowed to stand at room temperature for 45 min.

scholarly journals Useful Bioactive Substances from Wastes: Recovery of Trans-Resveratrol from Grapevine Stems

2016 ◽  
Vol 10 (1) ◽  
pp. 4-9 ◽  
Author(s):  
George Angelov ◽  
Lubomir Boyadzhiev ◽  
Silviya Georgieva
Keyword(s):  
Water Solubility ◽  
Pharmaceutical Preparations ◽  
Water Soluble ◽  
Raw Material ◽  
Bioactive Substances ◽  
Total Extract ◽  
Initial Extract ◽  
Efficient Extraction ◽  
Simple Extraction ◽  
The Many

The methods for producing natural resveratrol are of big interest because of the many health benefits of this substance and its increasing use in functional foods, food supplements and para-pharmaceutical preparations. Generally, resveratrol is extracted from different natural sources, most of them usually produced for consumption purposes (grapes, nuts). This paper presents a method for recovery of resveratrol from a widely available raw material - grapevine stems, a by-product of vine pruning. An efficient extraction-fractionation scheme is developed, based on shifting the phase equilibrium, by which more concentrated extracts of resveratrol are obtained. After a simple extraction, the initial extract is further separated into two fractions, containing either water or ethanol-soluble compounds. Using this approach, the resveratrol’s low water solubility helps isolate it from other water-soluble substances. The resulting product is almost ten times more concentrated in trans-resveratrol than the initial total extract. Additionally, a fraction containing water-soluble polyphenols is obtained, which could be used for water-based pharmaceutical and cosmetic preparations.

L-Histidine Stabilized Copper Nanoclusters as a Fluorescence Probe for Determination of Fluazinam

NANO ◽  
2020 ◽  
Vol 15 (05) ◽  
pp. 2050063
Author(s):  
Zhifeng Cai ◽  
Xiu Yin ◽  
Jingling Fang ◽  
Jie Zhao ◽  
Tianqi Wu ◽  
...  
Keyword(s):  
Fluorescence Intensity ◽  
Photoelectron Spectroscopy ◽  
Water Solubility ◽  
Fluorescence Probe ◽  
Synthesis Method ◽  
Fluorescence Emission ◽  
Average Diameter ◽  
High Dispersion ◽  
Excitation Wavelength ◽  
One Pot

In this contribution, a one-pot synthesis method possessing the advantages of simple, green and low-cost had been researched for the preparation of L-histidine-stabilized Cu nanoclusters (Cu NCs). Subsequently, the structure and optical properties of as-prepared Cu NCs were studied by using Fourier transform infrared (FTIR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), fluorescence spectroscopy and UV-Vis absorption spectroscopy. TEM image of the Cu NCs showed high dispersion with an average diameter of 2.0[Formula: see text]nm. Fluorescence spectrum displayed that the Cu NCs emitted green fluorescence (emission wavelength of 492[Formula: see text]nm) under excitation wavelength of 393[Formula: see text]nm. Moreover, the as-synthesized Cu NCs illustrated excellent performances, such as good water solubility, UV stability and high-salt resistance. Interestingly, the fluorescence intensity of as-prepared Cu NCs was obviously quenched in the presence of fluazinam. Under optimal conditions, the relative fluorescence intensity was linear with the fluazinam concentrations from 1 to 40[Formula: see text][Formula: see text]M, with a detection limit of 0.25[Formula: see text][Formula: see text]M. Eventually, the fluorescence sensor was successfully used to determine fluazinam in real water samples.

scholarly journals Green Synthesis of Lutein-Based Carbon Dots Applied for Free-Radical Scavenging within Cells

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4146 ◽  
Author(s):  
Dian Yang ◽  
Li Li ◽  
Lei Cao ◽  
Zhimin Chang ◽  
Qian Mei ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Water Solubility ◽  
Synthesis Method ◽  
Radical Scavenging ◽  
The Body ◽  
Raw Material ◽  
High Yield ◽  
Environmental Friendliness ◽  
Problems In Living ◽  
Living Organisms

Reactive oxygen species (ROS) in the body play an important role in various processes. It is well known that harmful high levels of ROS can cause many problems in living organisms in a variety of ways. One effective way to remove intracellular ROS is to use reducing materials that can enter the cell. Herein, we developed a strong reducing carbon nano-dot from a natural product, lutein, as an initial raw material. This is a hydrothermal synthesis method with the advantages of simplicity, high yield, mild reaction conditions, and environmental friendliness. The prepared carbon dots exhibit bright blue fluorescence, and have good water solubility and biocompatibility. In particular, the carbon dots can easily enter the cell and effectively remove ROS. Therefore, the carbon dots are thought to protect cells from oxidative damage by high levels of ROS.

One pot selective synthesis of water and organic soluble carbon dots with green fluorescence emission

RSC Advances ◽  
2015 ◽  
Vol 5 (15) ◽  
pp. 11667-11675 ◽  
Author(s):  
Baozhan Zheng ◽  
Tao Liu ◽  
Man Chin Paau ◽  
Meina Wang ◽  
Yang Liu ◽  
...  
Keyword(s):  
Energy Saving ◽  
Carbon Dots ◽  
Room Temperature ◽  
Fluorescence Emission ◽  
Water Soluble ◽  
Selective Synthesis ◽  
Green Fluorescence ◽  
One Pot ◽  
Soluble Carbon

This work reports a simple and energy-saving strategy for selective synthesis of water-soluble and organic-soluble carbon dots at room temperature.

Synthesis and Properties of the Composite DSD Acid-Triazine Structure Containing Long-Chain Quaternary Ammonium Fluorescent Brighteners

2012 ◽  
Vol 260-261 ◽  
pp. 83-86
Author(s):  
Ming Yang Wang ◽  
Mao Sheng Wan ◽  
Cheng Bo Cao
Keyword(s):  
Tertiary Amine ◽  
Quaternary Ammonium ◽  
Condensation Reaction ◽  
Fluorescence Emission ◽  
Raw Material ◽  
Amino Compound ◽  
Enhancement Effect ◽  
Uv Spectrum ◽  
Fluorescence Excitation ◽  
Long Chain

The cetyl \ octadecyl dimethyl tertiary amine（percentage composition 7:3）is a very common and inexpensive chemical raw material in the chemical market. In this paper, a series of the new chemical composite DSD acid-triazine structure containing long chain quaternary ammonium salt fluorescent brighteners (FBs) were synthesized through a three-step condensation reaction of cyanuric chloride, DSD acid, cetyl \ octadecyl dimethyl tertiary amine and amino compound. The obtained compounds were characterized by the analysis of the IR spectrum, UV spectrum and fluorescence excitation and emission spectrum, and whiteness were tested through dyeing filter paper. The results show that compounds 7a-j have the obvious UV absorption, fluorescence emission and dyeing properties, with a wider absorption, emission wavelength range and enhancing fluorescence quantum yield, achieving the synergetic enhancement effect by compounding.

scholarly journals One-Pot Hydrothermal Synthesis of Carbon Dots as Fluorescent Probes for the Determination of Mercuric and Hypochlorite Ions

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1831
Author(s):  
Hsin Lee ◽  
Yen-Chang Su ◽  
Hsiang-Hao Tang ◽  
Yu-Sheng Lee ◽  
Jan-Yee Lee ◽  
...  
Keyword(s):  
Fluorescence Intensity ◽  
Fluorescent Probes ◽  
Carbon Dots ◽  
Limit Of Detection ◽  
Tap Water ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Excitation Wavelength ◽  
One Pot ◽  
Fluorescence Emission Spectra

Nitrogen and sulfur codoped carbon dots (NSCDs) were synthesized via a one-pot hydrothermal method, and citric acid, ethylenediamine, and methyl blue were used as precursors. The obtained NSCDs were spherical with an average size of 1.86 nm. The fluorescence emission spectra of the NSCDs were excitation independent and emitted blue fluorescence at 440 nm with an excitation wavelength at 350 nm. The quantum yield of the NSCDs was calculated to be 68.0%. The NSCDs could be constructed as fluorescent probes for highly selective and sensitive sensing mercuric (Hg2+) and hypochlorite (ClO−) ions. As the addition of Hg2+ or ClO− ions to the NSCDs, the fluorescence intensity was effectively quenched due to dynamic quenching. Under the optimal conditions, the linear response of the fluorescence intensity ranged from 0.7 μM to 15 μM with a detection limit of 0.54 μM and from 0.3 μM to 5.0 μM with a limit of detection of 0.29 μM for Hg2+ and ClO− ions, respectively. Finally, the proposed method was successfully used for quantifying Hg2+ and ClO− ions in spiked tap water samples.

scholarly journals Naturally Derived Carbon Dots as Bioimaging Agents

2021 ◽  
Author(s):  
Gangaraju Gedda ◽  
Arun Bhupathi ◽  
V.L.N. Balaji Gupta Tiruveedhi
Keyword(s):  
Green Synthesis ◽  
Contrast Agents ◽  
Carbon Dots ◽  
Multimodal Imaging ◽  
Water Solubility ◽  
Imaging Techniques ◽  
Fluorescence Emission ◽  
Biological Properties ◽  
Synthesis Methods ◽  
High Fluorescence

The recent advances in nanoscience and technology have opened new avenues for carbon-based nanomaterials. Especially, Carbon dots (CDs) have gained significant attention due to their simple, economic and rapid green synthesis. These materials exhibit excellent water solubility, fluorescence emission, high fluorescence quantum yield, Ultraviolet (UV) to Infrared (IR) range absorbance and high bio-compatibility. Therefore, these materials are widely used for various biological applications including bio-imaging. With the integration and doping of surface passive agents and elements, respectively influenced the enhancement of fluorescence property of CDs. Also, the conjugation of receptor-based targeting ligands leads to targeted bioimaging. CDs in combination with other imaging contrast agents lead to the development of novel contrast agents for bimodal imaging and multimodal imaging techniques. The combination of diagnostic CDs with therapeutic agents resulted in the formation of theragnostic CDs for image guided therapies. In this chapter, a comprehensive view on the top-down and bottom–up green synthesis methods for naturally derived CDs discussed. Further, unique physical, chemical, optical and biological properties of CDs described. Finally, fluorescence based bimodal and multimodal imaging techniques also described.

scholarly journals Chromo- and fluorophoric water-soluble polymers and silica particles by nucleophilic substitution reaction of poly(vinyl amine)

2010 ◽  
Vol 6 ◽  
Author(s):  
Katja Hofmann ◽  
Ingolf Kahle ◽  
Frank Simon ◽  
Stefan Spange
Keyword(s):  
Fluorescence Spectroscopy ◽  
Photoelectron Spectroscopy ◽  
Model Compound ◽  
Water Solubility ◽  
Fluorescence Emission ◽  
Silica Particles ◽  
Water Soluble ◽  
Nucleophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
New Compounds

Novel chromophoric and fluorescent carbonitrile-functionalized poly(vinyl amine) (PVAm) and PVAm/silica particles were synthesized by means of nucleophilic aromatic substitution of 8-oxo-8H-acenaphtho[1,2-b]pyrrol-9-carbonitrile (1) with PVAm in water. The water solubility of 1 has been mediated by 2,6-O-β-dimethylcyclodextrin or by pre-adsorption onto silica particles. Furthermore, 1 was converted with isopropylamine into the model compound 1-M. All new compounds were characterized by NMR, FTIR, UV–vis and fluorescence spectroscopy. The solvent-dependent UV–vis absorption and fluorescence emission band positions of the model compound and the carbonitrile-functionalized PVAm were studied and interpreted using the empirical Kamlet–Taft solvent parameters π * (dipolarity/polarizability), α (hydrogen-bond donating capacity) and β (hydrogen-accepting ability) in terms of the linear solvation energy relationship (LSER). The solvent-independent regression coefficients a, b and s were determined using multiple linear correlation analysis. It is shown, that the chains of the polymer have a significant influence on the solvatochromic behavior of 1-P. The structure of the carbonitrile 1-Si bound to polymer-modified silica particles was studied by means of X-ray photoelectron spectroscopy (XPS) and Brunauer–Emmett–Teller (BET) measurements. Fluorescent silica particles were obtained as shown by fluorescence spectroscopy with a diffuse reflectance technique.

BODIPY Fluorophores for Membrane Potential Imaging

2019 ◽  
Author(s):  
Jenna Franke ◽  
Benjamin Raliski ◽  
Steven Boggess ◽  
Divya Natesan ◽  
Evan Koretsky ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Water Solubility ◽  
Water Soluble ◽  
Voltage Sensitivity ◽  
Chemical Transformations ◽  
Direct Modification ◽  
Biological Compatibility ◽  
Meso Position ◽  
Ionizable Groups ◽  
Boron Center

Fluorophores based on the BODIPY scaffold are prized for their tunable excitation and emission profiles, mild syntheses, and biological compatibility. Improving the water-solubility of BODIPY dyes remains an outstanding challenge. The development of water-soluble BODIPY dyes usually involves direct modification of the BODIPY fluorophore core with ionizable groups or substitution at the boron center. While these strategies are effective for the generation of water-soluble fluorophores, they are challenging to implement when developing BODIPY-based indicators: direct modification of BODIPY core can disrupt the electronics of the dye, complicating the design of functional indicators; and substitution at the boron center often renders the resultant BODIPY incompatible with the chemical transformations required to generate fluorescent sensors. In this study, we show that BODIPYs bearing a sulfonated aromatic group at the meso position provide a general solution for water-soluble BODIPYs. We outline the route to a suite of 5 new sulfonated BODIPYs with 2,6-disubstitution patterns spanning a range of electron-donating and -withdrawing propensities. To highlight the utility of these new, sulfonated BODIPYs, we further functionalize them to access 13 new, BODIPY-based voltage-sensitive fluorophores. The most sensitive of these BODIPY VF dyes displays a 48% ΔF/F per 100 mV in mammalian cells. Two additional BODIPY VFs show good voltage sensitivity (≥24% ΔF/F) and excellent brightness in cells. These compounds can report on action potential dynamics in both mammalian neurons and human stem cell-derived cardiomyocytes. Accessing a range of substituents in the context of a water soluble BODIPY fluorophore provides opportunities to tune the electronic properties of water-soluble BODIPY dyes for functional indicators.

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