scholarly journals Synthesis of hydrophilic and hydrophobic carbon quantum dots from waste of wine fermentation

2017 ◽  
Vol 4 (12) ◽  
pp. 170900 ◽  
Author(s):  
Massimo Varisco ◽  
Denis Zufferey ◽  
Albert Ruggi ◽  
Yucheng Zhang ◽  
Rolf Erni ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Manufacturing Industry ◽  
Animal Feed ◽  
Blue Emission ◽  
Luminescent Properties ◽  
Carbon Quantum Dots ◽  
Raw Material ◽  
Added Value ◽  
Wine Production ◽  
Bright Blue

Wine lees are one of the main residues formed in vast quantities during the fermentation of wine. While toxic when applied to plants and wetlands, it is a biodegradable material, and several alternatives have been proposed for its valorization as: dietary supplement in animal feed, source for various yeast extracts and bioconversion feedstock. The implementation of stricter environment protection regulations resulted in increasing costs for wineries as their treatment process constitutes an unavoidable and expensive step in wine production. We propose here an alternative method to reduce waste and add value to wine production by exploiting this rich carbon source and use it as a raw material for producing carbon quantum dots (CQDs). A complete synthetic pathway is discussed, comprising the carbonization of the starting material, the screening of the most suitable solvent for the extraction of CQDs from the carbonized mass and their hydrophobic or hydrophilic functionalization. CQDs synthesized with the reported procedure show a bright blue emission ( λ max  = 433 ± 13 nm) when irradiated at 366 nm, which is strongly shifted when the wavelength is increased (e.g. emission at around 515 nm when excited at 460 nm). Yields and luminescent properties of CQDs, obtained with two different methods, namely microwave and ultrasound-based extraction, are discussed and compared. This study shows how easy a residue can be converted into an added-value material, thus not only reducing waste and saving costs for the wine-manufacturing industry but also providing a reliable, affordable and sustainable source for valuable materials.

Carbon Quantum Dots as Fluorescence Turn-Off-On Probe for Detecting Fe3+ and Ascorbic Acid

2020 ◽  
Vol 20 (6) ◽  
pp. 3340-3347 ◽  
Author(s):  
Yong Zhang ◽  
Yanteng Xiao ◽  
Yujuan Zhang ◽  
Yingte Wang
Keyword(s):  
Quantum Dots ◽  
Ascorbic Acid ◽  
Fluorescence Probe ◽  
Fluorescent Sensor ◽  
Blue Emission ◽  
Carbon Quantum Dots ◽  
Emission Peak ◽  
Dual Function ◽  
Blue Emission Peak ◽  
Bright Blue

This work describes a “turn-off-on” fluorescence probe based on carbon quantum dots for sensing Fe3+ and ascorbic acid. The carbon quantum dots are prepared by hydrothermal method using a biocarbon source of black sesame. When excited at 355 nm, the carbon quantum dots show a strong bright blue emission peak centered at 438 nm. Obviously, the decrease of the fluorescence intensity of carbon quantum dots can be seen upon addition of Fe3+. Interestingly, the fluorescence quenching can be regained after the addition of ascorbic acid. The mechanism is that the added Fe3+ was destroyed by reductive ascorbic acid because of the redox reaction between ascorbic acid and Fe3+, making the fluorescence of the system recovered. The obtained curves are linear for Fe3+ and ascorbic acid over the range 50–1500 μM and 32.2–987.6 μM, respectively. The detection limits for Fe3+ and ascorbic acid are 2.78 μM and 0.0344 μM, respectively. Thus the carbon quantum dots can be used as a dual-function fluorescent sensor to achieve sensitive detection of Fe3+ and ascorbic acid.

Green and efficient synthesis of carbon quantum dots and their luminescent properties

2019 ◽  
Vol 206 ◽  
pp. 158-163 ◽  
Author(s):  
Langfeng Zhou ◽  
Meng Qiao ◽  
Lei Zhang ◽  
Lu Sun ◽  
Yang Zhang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Luminescent Properties ◽  
Carbon Quantum Dots ◽  
Efficient Synthesis

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 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.

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.

Cuttlefish ink-based N and S co-doped carbon quantum dots as fluorescent sensor for highly sensitive and selective para-nitrophenol detection

2021 ◽  
Author(s):  
Xiaotong Huang ◽  
Chunli Yang ◽  
Yingxin Chen ◽  
Zebin Zhu ◽  
Lihua Zhou
Keyword(s):  
Quantum Dots ◽  
Organic Synthesis ◽  
Fluorescent Sensor ◽  
Environmental Problems ◽  
Carbon Quantum Dots ◽  
Raw Material ◽  
Highly Sensitive ◽  
Co Doped

Para-nitrophenol (PNP) is an important raw material for organic synthesis and its extensive use has produced a series of environmental problems. Here, we develop a highly sensitive and selective fluorescent...

scholarly journals Fluorescent Carbon Quantum Dots—Synthesis, Functionalization and Sensing Application in Food Analysis

Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 930 ◽  
Author(s):  
Mingfei Pan ◽  
Xiaoqian Xie ◽  
Kaixin Liu ◽  
Jingying Yang ◽  
Liping Hong ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Food Analysis ◽  
Carbon Nanomaterials ◽  
Carbon Quantum Dots ◽  
Food Composition ◽  
Raw Material ◽  
Research Progress ◽  
Composition Analysis ◽  
Sensing Applications ◽  
New Material

Carbon quantum dots (CQDs) with stable physicochemical properties are one of the emerging carbon nanomaterials that have been studied in recent years. In addition to the excellent optical properties such as photoluminescence, photobleaching resistance and light stability, this material also has favorable advantages of good biocompatibility and easy functionalization, which make it an ideal raw material for constructing sensing equipment. In addition, CQDs can combined with other kinds of materials to form the nanostructured composites with unique properties, which provides new insights and ideas for the research of many fields. In the field of food analysis, emerging CQDs have been deeply studied in food composition analysis, detection and monitoring trace harmful substances and made remarkable research progress. This article introduces and compares the various methods for CQDs preparation and reviews its related sensing applications as a new material in food components analysis and food safety inspection in recent years. It is expected to provide a significant guidance for the further study of CQDs in the field of food analysis and detection.

scholarly journals The Potential of Selected Agri-Food Loss and Waste to Contribute to a Circular Economy: Applications in the Food, Cosmetic and Pharmaceutical Industries

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 515
Author(s):  
Lady Laura Del Rio Osorio ◽  
Edwin Flórez-López ◽  
Carlos David Grande-Tovar
Keyword(s):  
Circular Economy ◽  
Animal Feed ◽  
Raw Materials ◽  
Pharmaceutical Products ◽  
Raw Material ◽  
Added Value ◽  
Food Loss ◽  
Pharmaceutical Industries ◽  
Scarcity Of Resources ◽  
By Products

The food sector includes several large industries such as canned food, pasta, flour, frozen products, and beverages. Those industries transform agricultural raw materials into added-value products. The fruit and vegetable industry is the largest and fastest-growing segment of the world agricultural production market, which commercialize various products such as juices, jams, and dehydrated products, followed by the cereal industry products such as chocolate, beer, and vegetable oils are produced. Similarly, the root and tuber industry produces flours and starches essential for the daily diet due to their high carbohydrate content. However, the processing of these foods generates a large amount of waste several times improperly disposed of in landfills. Due to the increase in the world’s population, the indiscriminate use of natural resources generates waste and food supply limitations due to the scarcity of resources, increasing hunger worldwide. The circular economy offers various tools for raising awareness for the recovery of waste, one of the best alternatives to mitigate the excessive consumption of raw materials and reduce waste. The loss and waste of food as a raw material offers bioactive compounds, enzymes, and nutrients that add value to the food cosmetic and pharmaceutical industries. This paper systematically reviewed literature with different food loss and waste by-products as animal feed, cosmetic, and pharmaceutical products that strongly contribute to the paradigm shift to a circular economy. Additionally, this review compiles studies related to the integral recovery of by-products from the processing of fruits, vegetables, tubers, cereals, and legumes from the food industry, with the potential in SARS-CoV-2 disease and bacterial diseases treatment.

scholarly journals Screening of Fungal Strains for Cellulolytic and Xylanolytic Activities Production and Evaluation of Brewers’ Spent Grain as Substrate for Enzyme Production by Selected Fungi

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4443
Author(s):  
Rossana Liguori ◽  
Anna Pennacchio ◽  
Luciana Porto de Souza Vandenberghe ◽  
Addolorata De Chiaro ◽  
Leila Birolo ◽  
...  
Keyword(s):  
Enzyme Production ◽  
Animal Feed ◽  
Fungal Growth ◽  
Cellulase Production ◽  
Raw Material ◽  
Added Value ◽  
Xylanase Production ◽  
Solid Media ◽  
Spent Grain ◽  
Beer Production

Brewer’s spent grain (BSG), the solid residue of beer production, is attracting significant attention as raw material for the production of added value substances, since until recently it was mainly used as animal feed or deposited in landfills, causing serious environmental problems. Therefore, this work aimed at developing a bioprocess using BSG as a substrate for the production of cellulases and xylanases for waste saccharification and bioenergy production. Different fungi were analyzed for their cellulolytic and xylanolytic abilities, through a first screening on solid media by assessment of fungal growth and enzyme production on agar containing carboxylmethylcellulose or xylan as the sole carbon source, respectively. The best cellulase and xylanase producers were subjected to quantitative evaluation of enzyme production in liquid cultures. Aspergillus niger LPB-334 was selected for its ability to produce cellulase and xylanase at high levels and it was cultivated on BSG by solid state fermentation. The cellulase production reached a maximum of 118.04 ± 8.4 U/g of dry substrate after 10 days of fermentation, while a maximum xylanase production of 1315.15 ± 37.5 U/g of dry substrate was reached after 4 days. Preliminary characterization of cellulase and xylanase activities and identification of the enzymes responsible were carried out.

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