Highly Enhanced Enzymatic Activity of Mn-Induced Carbon Dots and Their Application as Colorimetric Sensor Probes

Nanomaterial-based enzyme mimetics (nanozymes) have attracted significant interest because of their lower cost and higher stability compared to natural enzymes. In this study, we focused on improving the enzymatic properties of metal induced N-doped carbon dots (N-CDs), which are nanozymes of interest, and their applications for sensory systems. For this purpose, Mn(acetate)2 was introduced during the synthetic step of N-doped carbon dots, and its influence on the enzymatic properties of Mn-induced N-CDs (Mn:N-CDs) was investigated. Their chemical structure was analyzed through infrared spectroscopy and X-ray photoelectron spectrometry; the results suggest that Mn ions lead to the variation in the population of chemical bonding in Mn:N-CDs, whereas these ions were not incorporated into N-CD frameworks. This structural change improved the enzymatic properties of Mn:N-CDs with respect to those of N-CDs when the color change of a 3,3′,5,5′-tetramethylbenzidine/H2O2 solution was examined in the presence of Mn:N-CDs and N-CDs. Based on this enhanced enzymatic property, a simple colorimetric system with Mn:N-CDs was used for the detection of γ-aminobutyric acid, which is an indicator of brain-related disease. Therefore, we believe that Mn:N-CDs will be an excellent enzymatic probe for the colorimetric sensor system.

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Nitrogen and Sulfur Co-doped Fluorescent Carbon Dots for the Detection of Morin and Cell Imaging

Current Analytical Chemistry ◽

10.2174/1573411014666180904104629 ◽

2018 ◽

Vol 15 (1) ◽

pp. 47-55

Author(s):

Xuebing Li ◽

Haifen Yang ◽

Ning Wang ◽

Tijian Sun ◽

Wei Bian ◽

...

Keyword(s):

Microwave Heating ◽

Fluorescent Probe ◽

Fluorescence Intensity ◽

Carbon Dots ◽

Cell Imaging ◽

Water Soluble ◽

Heating Process ◽

X Ray ◽

Doped Carbon Dots ◽

Co Doped

Background: Morin has many pharmacological functions including antioxidant, anticancer, anti-inflammatory, and antibacterial effects. It is commonly used in the treatment of antiviral infection, gastropathy, coronary heart disease and hepatitis B in clinic. However, researches have shown that morin is likely to show prooxidative effects on the cells when the amount of treatment is at high dose, leading to the decrease of intracellular ATP levels and the increase of necrosis process. Therefore, it is necessary to determine the concentration of morin in biologic samples. Method: Novel water-soluble and green nitrogen and sulfur co-doped carbon dots (NSCDs) were prepared by a microwave heating process with citric acid and L-cysteine. The fluorescence spectra were collected at an excitation wavelength of 350 nm when solutions of NSCDs were mixed with various concentrations of morin. Results: The as-prepared NSCDs were characterized by transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The fluorescence intensity of NSCDs decreased significantly with the increase of morin concentration. The fluorescence intensity of NSCDs displayed a linear response to morin in the concentration 0.10-30 μM with a low detection limit of 56 nM. The proposed fluorescent probe was applied to analysis of morin in human body fluids with recoveries of 98.0-102%. Conclusion: NSCDs were prepared by a microwave heating process. The present analytical method is sensitive to morin. The quenching process between NSCDs and morin is attributed to the static quenching. In addition, the cellular toxicity on HeLa cells indicated that the as-prepared NSCDs fluorescent probe does not show obvious cytotoxicity in cell imaging. Our proposed method possibly opens up a rapid and nontoxic way for preparing heteroatom doped carbon dots with a broad application prospect.

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Nitrogen-doped carbon dots as a probe for the detection of Cu2+ and its cellular imaging

Journal of Chemical Research ◽

10.1177/1747519819875046 ◽

2019 ◽

Vol 43 (11-12) ◽

pp. 507-515 ◽

Cited By ~ 1

Author(s):

Ning Wang ◽

Xuebing Li ◽

Xuefang Yang ◽

Zenglian Tian ◽

Wei Bian ◽

...

Keyword(s):

Fluorescence Intensity ◽

Photoelectron Spectroscopy ◽

Carbon Dots ◽

Ph Value ◽

Tap Water ◽

Experimental Conditions ◽

X Ray ◽

Nitrogen Doped ◽

Doped Carbon Dots ◽

Nitrogen Doped Carbon

Nitrogen-doped carbon dots were synthesized using citric acid monohydrate and glutathione as raw materials. The synthesized nitrogen-doped carbon dots were characterized by multiple analytical techniques, including transmission electron microscopy, Fourier transform infrared spectroscopy, ultraviolet–visible absorption spectroscopy, X-ray photoelectron spectroscopy, X-ray diffractometry, and fluorescence spectra. The fluorescence intensity of the nitrogen-doped carbon dots gradually quenched with different concentrations of Cu2+ ions. The effect of the pH value, the nitrogen-doped carbon dot concentration, and the reaction time on the fluorescence intensity of the N-CDs-Cu2+ system was investigated, and the experimental conditions were optimized. A rapid and sensitive method for the determination of Cu2+ ions was established that exhibited a good linearity in the concentration range 0.20–200.0 μM with a detection limit of 0.27 nM. Meanwhile, the fluorescence quenching mechanism of the interaction between nitrogen-doped carbon dots and Cu2+ was preliminarily discussed. The method was used to detect trace Cu2+ in tap water and lake water, with recoveries ranging from 98.1% to 102.0%. Furthermore, due to low cytotoxicity and good biocompatibility, nitrogen-doped carbon dots as a probe were also successfully used in bioimaging.

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The Detection of Osthole and Application of Cell Imaging Based on Nitrogen-Doped Carbon Dots

NANO ◽

10.1142/s1793292020500253 ◽

2020 ◽

Vol 15 (02) ◽

pp. 2050025

Author(s):

Ning Wang ◽

Xuefang Yang ◽

Haojiang Wang ◽

Liping Xie ◽

Weihua Jia ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Carbon Dots ◽

Cell Imaging ◽

Fluorescence Probe ◽

Experimental Conditions ◽

X Ray ◽

Nitrogen Doped ◽

High Fluorescence ◽

Doped Carbon Dots ◽

Nitrogen Doped Carbon

A fluorescence probe has been synthesized for the detection of osthole using the nitrogen-doped carbon dots (NCDs) as shown in Fig. 1. The NCDs were fully characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR). Under the optimal experimental conditions, the NCDs fluorescence probe was highly selective and sensitive to osthole. The linear response range for osthole was 5.0–75[Formula: see text][Formula: see text]M with a detection limit of 38[Formula: see text]nM. The mechanism of the interaction of osthole and NCDs was discussed. The fluorescence probe has been applied to the analysis of biological samples. The as-synthesized NCDs with high fluorescence intensity, low toxicity and good biocompatibility were applied to cell imaging.

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Engineering iodine-doped carbon dots as dual-modal probes for fluorescence and X-ray CT imaging

International Journal of Nanomedicine ◽

10.2147/ijn.s82778 ◽

2015 ◽

pp. 6943 ◽

Cited By ~ 11

Author(s):

Fengyi Du ◽

Miaomiao Zhang ◽

Huixiang Ju ◽

Li Zhang ◽

Mingzhong Sun ◽

...

Keyword(s):

Carbon Dots ◽

Ct Imaging ◽

X Ray ◽

Doped Carbon Dots

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Heteroatom Doped Carbon Dots with Nanoenzyme Like Properties as Theranostic Platforms for Free Radical Scavenging, Imaging, and Chemotherapy

SSRN Electronic Journal ◽

10.2139/ssrn.3527826 ◽

2020 ◽

Cited By ~ 1

Author(s):

Khalilalrahman Dehvari ◽

Sheng-Hui Chiu ◽

Jin-Sheng Lin ◽

Wubshet Mekonnen Girm ◽

Yong-Chien Ling ◽

...

Keyword(s):

Free Radical ◽

Carbon Dots ◽

Radical Scavenging ◽

Free Radical Scavenging ◽

Doped Carbon Dots

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Multifunctional N,S co-doped carbon dots for sensitive probing of temperature, ferric ion, and methotrexate

Analytical and Bioanalytical Chemistry ◽

10.1007/s00216-019-01617-4 ◽

2019 ◽

Vol 411 (8) ◽

pp. 1647-1657 ◽

Cited By ~ 7

Author(s):

Pengli Zuo ◽

Jianhua Liu ◽

Hongna Guo ◽

Chenghong Wang ◽

Hongqian Liu ◽

...

Keyword(s):

Carbon Dots ◽

Ferric Ion ◽

Doped Carbon Dots ◽

Co Doped

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Triggered peroxidase-like activity of Au decorated carbon dots for colorimetric monitoring of Hg2+ enrichment in Chlorella vulgaris

The Analyst ◽

10.1039/d0an00930j ◽

2020 ◽

Vol 145 (16) ◽

pp. 5500-5507

Author(s):

Wene Liu ◽

Lili Tian ◽

Jie Du ◽

Jiangmin Wu ◽

Yongmei Liu ◽

...

Keyword(s):

Chlorella Vulgaris ◽

Carbon Dots ◽

Colorimetric Sensor

Schematic illustration of a Hg2+ colorimetric sensor based on the Hg2+ triggered peroxidase-like activity of GNP@CDs.

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Novel Carbon Dots Derived from Glycyrrhizae Radix et Rhizoma and Their Anti-Gastric Ulcer Effect

Molecules ◽

10.3390/molecules26061512 ◽

2021 ◽

Vol 26 (6) ◽

pp. 1512

Author(s):

Yuhan Liu ◽

Meiling Zhang ◽

Jinjun Cheng ◽

Yue Zhang ◽

Hui Kong ◽

...

Keyword(s):

Gastric Ulcer ◽

Photoelectron Spectroscopy ◽

Carbon Dots ◽

High Performance ◽

Raw264.7 Cells ◽

Mice Model ◽

X Ray ◽

Glycyrrhizae Radix ◽

Transmission Electron ◽

High Resolution Tem

Glycyrrhizae Radix et Rhizoma (GRR) is one of the commonly used traditional Chinese medicines in clinical practice, which has been applied to treat digestive system diseases for hundreds of years. GRR is preferred for anti-gastric ulcer, however, the main active compounds are still unknown. In this study, GRR was used as precursor to synthesize carbon dots (CDs) by a environment-friendly one-step pyrolysis process. GRR-CDs were characterized by using transmission electron microscopy, high-resolution TEM, fourier transform infrared, ultraviolet-visible and fluorescence spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction and high-performance liquid chromatography. In addition, cellular toxicity of GRR-CDs was studied by using CCK-8 in RAW264.7 cells, and the anti-gastric ulcer activity was evaluated and confirmed using mice model of acute alcoholic gastric ulcer. The experiment confirmed that GRR-CDs were the spherical structure with a large number of active groups on the surface and their particle size ranged from 2 to 10 nm. GRR-CDs had no toxicity to RAW264.7 cells at concentration of 19.5 to 5000 μg/mL and could reduce the oxidative damage of gastric mucosa and tissues caused by alcohol, as demonstrated by restoring expression of malondialdehyde, superoxide dismutase and nitric oxide in serum and tissue of mice. The results indicated the explicit anti-ulcer activity of GRR-CDs, which provided a new insights for the research on effective material basis of GRR.

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