Design of carbon quantum dots via hydrothermal carbonization synthesis from renewable precursors

Carbon quantum dots (CQDs) are nanomaterials with a particle size range of 2 to 10 nm. CQDs have a wide range of applications such as medical diagnostics, bio-imaging, biosensors, coatings, solar cells, and photocatalysis. Although the effect of various experimental parameters, such as the synthesis method, reaction time, etc., have been investigated, the effect of different feedstocks on CQDs has not been studied yet. In this study, CQDs were synthesized from hydroxymethylfurfural, furfural, and microcrystalline cellulose via hydrothermal carbonization at 220 °C for 30 min of residence time. The produced CQDs showed green luminescence behavior under the short-wavelength UV light. Furthermore, the optical properties of CQDs were investigated using ultraviolet-visible spectroscopy and emission spectrophotometer, while the morphology and chemical bonds of CQDs were investigated using transmission electron microscopy and Fourier-transform infrared spectroscopy, respectively. Results showed that all CQDs produced from various precursors have absorption and emission properties but these optical properties are highly dependent on the type of precursor. For instance, the mean particle sizes were 6.36 ± 0.54, 5.35 ± 0.56, and 3.94 ± 0.60 nm for the synthesized CQDs from microcrystalline cellulose, hydroxymethylfurfural, and furfural, respectively, which appeared to have similar trends in emission intensities. In addition, the synthesized CQDs experienced different functionality (e.g., C=O, O-H, C-O) resulting in different absorption behavior.

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Synthesis of Carbon Quantum Dots from Food Products by Hydrothermal Carbonization Method

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/877/1/012010 ◽

2020 ◽

Vol 877 ◽

pp. 012010

Author(s):

Z Iwińska ◽

P Pietrusiewicz

Keyword(s):

Quantum Dots ◽

Food Products ◽

Hydrothermal Carbonization ◽

Carbon Quantum Dots

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

International Journal of Molecular Sciences ◽

10.3390/ijms21218073 ◽

2020 ◽

Vol 21 (21) ◽

pp. 8073 ◽

Cited By ~ 1

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.

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Nitrogen, Copper-doped Carbon Quantum Dots with Intrinsic Peroxidase-like Activity for Double-signals Detection of Phenol

The Analyst ◽

10.1039/d1an00796c ◽

2021 ◽

Author(s):

Jinyan Du ◽

Shuangqing Qi ◽

Tingting Fan ◽

Ying Yang ◽

Chaofeng Wang ◽

...

Keyword(s):

Quantum Dots ◽

Hydrothermal Carbonization ◽

Carbon Quantum Dots ◽

One Step ◽

Synthesis Procedure

Herein, a simple and facile one-step hydrothermal carbonization synthesis procedure for the fabrication of N, Cu-doped carbon quantum dots (N, Cu-CQDs) as a peroxidase-mimicking enzyme was reported. The peroxidase-like performance...

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Carbon Quantum Dots Prepared with Chitosan for Synthesis of CQDs/AuNPs for Iodine Ions Detection

Nanomaterials ◽

10.3390/nano8121043 ◽

2018 ◽

Vol 8 (12) ◽

pp. 1043 ◽

Cited By ~ 11

Author(s):

Juanjuan Song ◽

Li Zhao ◽

Yesheng Wang ◽

Yun Xue ◽

Yujia Deng ◽

...

Keyword(s):

Quantum Dots ◽

Color Change ◽

Colorimetric Method ◽

High Sensitivity ◽

Hydrothermal Carbonization ◽

Carbon Quantum Dots ◽

Water Soluble ◽

Synthetic Process ◽

Iodide Ions

Water-soluble and reductive carbon quantum dots (CQDs) were fabricated by the hydrothermal carbonization of chitosan. Acting as a reducing agent and stabilizer, the as-prepared CQDs were further used to synthesize gold nanoparticles (AuNPs). This synthetic process was carried out in aqueous solution, which was absolutely “green”. Furthermore, the CQDs/AuNPs composite was used to detect iodine ions by the colorimetric method. A color change from pink to colorless was observed with the constant addition of I− ions, accompanied by a decrease in the absorbance of the CQDs/AuNPs composite. According to the absorbance change, a favorable linear relationship was obtained between ΔA and I− concentration in the range of 20–140 μM and 140–400 μM. The detection limit of iodide ions, depending on the 3δ/slope, was estimated to be 2.3 μM, indicating high sensitivity to the determination of iodide. More importantly, it also showed good selectivity toward I− over other anion ions, and was used for the analysis of salt samples. Moreover, TEM results indicated that I− ions induced the aggregation of CQDs/AuNPs, resulting in changes in color and absorbance.

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Carbon Quantum Dots : Synthesis and Optronics Applications

10.24001/icsesd2017.25 ◽

2017 ◽

Author(s):

Swati S. Soley

Keyword(s):

Quantum Dots ◽

Carbon Quantum Dots

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LUMINESCENT DETERMINATION OF SUGAR IN NATURAL HONEY

Izvestia Ufimskogo Nauchnogo Tsentra RAN ◽

10.31040/2222-8349-2020-0-4-29-32 ◽

2020 ◽

Vol 0 (4) ◽

pp. 29-32

Author(s):

B.M. GAREEV ◽

◽

A.M. ABDRAKHMANOV ◽

G.L. SHARIPOV ◽

◽

...

Keyword(s):

Quantum Dots ◽

Laboratory Test ◽

Aqueous Solutions ◽

Analytical Method ◽

Sugar Content ◽

Carbon Quantum Dots ◽

Photoluminescence Intensity ◽

Sucrose Content ◽

Natural Honey

The photoluminescence of carbon quantum dots synthesized from natural honey and mixtures of honey and sugar has been studied. An increase in the sugar content leads to a decrease in the photoluminescence intensity without changing the shape of the luminescence spectrum of these quantum dots aqueous solutions, which is associated with a decrease in the yield of their synthesis in the sugar presence. The discovered effect can be used to detect sugar in honey. When examining five different market samples of flower honey using this method, two of them showed a significant decrease in the photoluminescence intensity. A laboratory test for compliance with GOST 19792-2017 Standard requirements established an excess of the sucrose content in these samples. Luminescent determination of sugar in honey does not require complicated equipment and can be used to develop a new analytical method for determining the sugar content in counterfeit natural honey.

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