Synthesis of Multi-Color Fluorescent Carbon Dots From Mint Leaves: A Robust Bioimaging Agent with Potential Antioxidant Activity

2020 ◽  
Vol 20 (10) ◽  
pp. 6305-6316 ◽  
Author(s):  
Sadia Shahid ◽  
Shanid Mohiyuddin ◽  
Gopinath Packirisamy
Keyword(s):  
Antioxidant Activity ◽  
Carbon Dots ◽  
Practical Implication ◽  
Chemical Properties ◽  
Surface States ◽  
Ultra Violet ◽  
Antioxidant Property ◽  
X Ray ◽  
Transmission Electron ◽  
Multiple Routes

Carbon dots (C-dots), a promising luminescent nanomaterial with exceptional physico-chemical properties gaining enormous attention in recent years. Carbon dots having enhanced biocompatibility and multiple routes of synthesis offers a promising substitute to luminescent quantum dots (QD). Further, wavelength-controlled emission features of C-dots proved as a good candidate in the biolabeling applications. Herein, we are reporting a facile and one-step hydrothermal synthesis of biocompatible multi-color, Polyethyleneimine (PEI) surface passivated C-dots (CDP) from mint leaves as a green source. The morphological and optical properties of C-dots have been extensively studied by Zeta-sizer, Transmission electron microscopy (TEM), X-ray diffraction (XRD) pattern, Ultra violet (UV)-visible spectroscopy and fluorescence spectroscopic analysis. Furthermore, Fourier transform infrared (FT-IR) and X-Ray Photoelectron Spectroscopic (XPS) analysis have been performed for the understanding of surface states and chemical composition of C-dots. A comparative analysis in the biolabeling potentials of non-passivated C-dots (CD) and CDP was conducted in the breast cancer (MCF-7) cells and the concentration dependent cytotoxicity was estimated. Further, an enhanced antioxidant property was showed by CDP as compared to CD. In the present study, a practical implication of C-dots synthesized from a herbal source (mint) to serve as a novel agent for various biolabeling applications and antioxidant activity have been experimentally resolved. As synthesized CD and CDP can be, serve as better alternatives for imaging probe with improved biocompatibility.

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

Molecules ◽  
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.

scholarly journals Non-Enzymatic Glucose Sensing Based on Incorporation of Carbon Nanotube into Zn-Co-S Ball-in-Ball Hollow Sphere

Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4340
Author(s):  
Han-Wei Chang ◽  
Chia-Wei Su ◽  
Jia-Hao Tian ◽  
Yu-Chen Tsai
Keyword(s):  
Electron Microscopy ◽  
Hollow Sphere ◽  
Photoelectron Spectroscopy ◽  
Chemical Properties ◽  
High Sensitivity ◽  
Glucose Sensing ◽  
Ionic Exchange ◽  
X Ray ◽  
Transmission Electron ◽  
Electro Oxidation

Zn-Co-S ball-in-ball hollow sphere (BHS) was successfully prepared by solvothermal sulfurization method. An efficient strategy to synthesize Zn-Co-S BHS consisted of multilevel structures by controlling the ionic exchange reaction was applied to obtain great performance electrode material. Carbon nanotubes (CNTs) as a conductive agent were uniformly introduced with Zn-Co-S BHS to form Zn-Co-S BHS/CNTs and expedited the considerable electrocatalytic behavior toward glucose electro-oxidation in alkaline medium. In this study, characterization with scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) was used for investigating the morphological and physical/chemical properties and further evaluating the feasibility of Zn-Co-S BHS/CNTs in non-enzymatic glucose sensing. Electrochemical methods (cyclic voltammetry (CV) and chronoamperometry (CA)) were performed to investigate the glucose sensing performance of Zn-Co-S BHS/CNTs. The synergistic effect of Faradaic redox couple species of Zn-Co-S BHS and unique conductive network of CNTs exhibited excellent electrochemical catalytic ability towards the glucose electro-oxidation, which revealed linear range from 5 to 100 μM with high sensitivity of 2734.4 μA mM−1 cm−2, excellent detection limit of 2.98 μM, and great selectivity in the presence of dopamine, uric acid, ascorbic acid, and fructose. Thus, Zn-Co-S BHS/CNTs would be expected to be a promising material for non-enzymatic glucose sensing.

Green preparation of carbon dots for Hg2+ detection and cell imaging

2020 ◽  
Vol 10 (11) ◽  
pp. 1777-1787
Author(s):  
Yadian Xie ◽  
Shanshan Wang ◽  
Ning Fu ◽  
Yan Yang ◽  
Xingliang Liu ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Carbon Dots ◽  
High Sensitivity ◽  
Amorphous Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbon And Nitrogen ◽  
Transmission Electron ◽  
Sensitivity And Selectivity ◽  
Ft Ir

Carbon dots (CDs) also nitrogen-doped CDs (N-CDs) were produced by green hydrothermal synthesis using Pea and ethanediamine as the carbon and nitrogen source, separately. Transmission electron microscopy (TEM) images displayed that the prepared CDs and N-CDs were well dispersed, had a spherical morphology. X-ray diffraction (XRD) figures of CDs and N-CDs presented a graphitic amorphous structure. Fourier transform infrared spectroscopy (FT-IR) verified that CDs and N-CDs carried many different hydrophilic groups (for example hydroxyl, carboxyl/carbonyl, amide, amino groups) on the surface, X-ray photoelectron spectroscopy (XPS) together verified this result. However, the optical properties and fluorescence quantum yield for N-CDs were obviously superior to those of CDs. Furthermore, the prepared N-CDs displayed outstanding advantages including low toxicity, satisfactory biocompatibility, and excellent chemical stability. More prominently, the prepared N-CDs could detect Hg2+ ions with high sensitivity and selectivity in both water samples and HeLa cells.

Influence of the Surfactant on the CdTe Nanomaterials Morphology

2011 ◽  
Vol 287-290 ◽  
pp. 294-297
Author(s):  
Cui Zhi Dong ◽  
Li Fang Zhang ◽  
Xiao Yan Wang ◽  
Ming Xi Zhang ◽  
Zhi Min Cui ◽  
...  
Keyword(s):  
Room Temperature ◽  
Chemical Properties ◽  
Semiconductor Materials ◽  
Alkaline Condition ◽  
Microemulsion System ◽  
X Ray ◽  
Cdte Nanoparticles ◽  
Ctab Concentration ◽  
Transmission Electron ◽  
And Chemical Properties

Because of the good photoelectric learning properties and chemical properties, CdTe nanocrystalline as an important Ⅱ-Ⅵ clan semiconductor materials has been used in LEDs, photonics, in aspects of materials and biomarker and so on. W/O microemulsion method has the peculiarity of tester simpleness, easy manipulation, room temperature react etc. In this paper CdTe nanoparticles was synthesized in CTAB/cyclohexane/isobutanol/water quatemary microemulsion system in alkaline condition and nitrogen. The morphology of the final products were characterized by X-ray power diffraction, transmission electron microscopy. according to the means, this paper researches the effect of surfactant contentration to morphology. The result is that the different morphology can be obtained through the different CTAB concentration. Finally, according to TEM chart, this paper infers the formation mechanism of the CdTe.

Study on Band Gap Energy of F Doped TiO2 Nanotubes

2017 ◽  
Vol 889 ◽  
pp. 234-238
Author(s):  
Mohd Hasmizam Razali ◽  
Nur Arifah Ismail ◽  
Mahani Yusoff
Keyword(s):  
Band Gap ◽  
Diffuse Reflectance Spectroscopy ◽  
Small Diameter ◽  
Ultra Violet ◽  
Band Gap Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gap Energy ◽  
Transmission Electron ◽  
Xrd Patterns

Pure and F doped TiO2 nanotubes was synthesized using simple hydrothermal method. The hydrothermal was conducted using teflon-liner autoclave and maintained at 150oC for 24 hours. The characterization of synthesised product was carried out using x-ray diffraction (XRD), transmission electron microscope (TEM), energy dispersive of x-ray spectroscopy (EDX) and ultra violet – visible light diffuse reflectance spectroscopy (UV-Vis DRS) for band gap measurements. XRD patterns indicated that anatase TiO2 phase was remained after F doping suggested that fluorine was highly dispersed into TiO2 by substituted with O in the TiO2 lattice to formed TiO2-xFx solid solution. Morphology investigation using TEM found out small diameter of nanotubes structure within 8 – 10 nm of pure and F doped TiO2 nanotubes. The band gap energy (Eg) of both nanotubes samples were almost similar proposing that F doping does not modify the band gap energy.

scholarly journals Structural and Chemical Properties of Geopolymer Gels Incorporated with Neodymium and Samarium

Gels ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 195
Author(s):  
Snežana S. S. Nenadović ◽  
Ljiljana M. Kljajević ◽  
Marija M. Ivanović ◽  
Miljana M. Mirković ◽  
Nadežda Radmilović ◽  
...  
Keyword(s):  
Rare Earth ◽  
Photoelectron Spectroscopy ◽  
Chemical Properties ◽  
Alkali Activation ◽  
Tetrahedral Coordination ◽  
X Ray Diffraction ◽  
Tem Analysis ◽  
X Ray ◽  
Transmission Electron ◽  
Na Ions

The present work was focused on doping of 1% and 5% both of Nd2O3 and Sm2O3 in geopolymer gels. One of the main goals was to determine the influence of the behavior of Nd and Sm as dopants and structural nanoparticles changes of the final geopolymer formed. It is shown that the disorder formed by alkali activation of metakaolin can accommodate the rare earth cations Nd3+ and Sm3+ into their aluminosilicate framework structure. The main geopolymerization product identified in gels is Al-rich (Na)-AS-H gel comprising Al and Si in tetrahedral coordination. Na+ ions were balancing the negative charge resulting from Al3+ in tetrahedral coordination. The changes in the structures of the final product (geopolymer/Nd2O3; Sm2O3), has been characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) analysis with energy dispersive spectrometry (EDS). Nucleation at the seed surfaces leads to the formation of phase-separated gels from rare earth phase early in the reaction process. It is confirmed that Nd and Sm have been shown to form unstable hydroxides Nd(OH)3 and Sm(OH)3 that are in equilibrium with the corresponding oxides.

Dirac States of 2D Topological Insulators: Effect of Heterovalent Dopant-Content

2019 ◽  
Vol 25 (6) ◽  
pp. 1437-1441 ◽  
Author(s):  
Salma Khatun ◽  
Amlan J. Pal
Keyword(s):  
Fermi Energy ◽  
Dirac Point ◽  
Surface States ◽  
Scanning Tunneling Spectroscopy ◽  
Scanning Tunneling ◽  
Metallic State ◽  
X Ray Diffraction ◽  
Dopant Content ◽  
X Ray ◽  
Transmission Electron

AbstractWe have studied Bi2Se3 at its 2D-limit using scanning tunneling spectroscopy (STS). Bulk Bi2Se3 is a well-known topological insulator having gapless surface states. In the 2D limit, the interior of the material exhibits a band gap, whereas the periphery shows a gapless metallic state having a Dirac point. We demonstrate a method to tune the Fermi energy and hence the Dirac point of Bi2Se3 nanoplates through doping at the anionic site. For this purpose, STS measurements were carried out on the Bi2Se3 system. We have used bromide as a dopant, which turns the material to n-type in nature. As a result, STS studies infer that the Fermi energy (EF) shifted toward the conduction band and consequently the Dirac point could be found to move away from Fermi energy. Through STS measurements, we have demonstrated a correlation between the shift of Dirac point position and the dopant content. The size, shape, and compositions of Bi2Se3 nanoflakes and concentration of bromine in the doped nanostructures were determined using transmission electron microscopy, associated energy dispersive X-ray spectroscopy analysis, and X-ray diffraction.

Study of Antioxidant Property of the Endosperm Extract of Borassus flabellifer (Taal) and its use in the green synthesis of Gold nanoparticles

2017 ◽  
Vol 1 (2) ◽  
Author(s):  
Sk Nurul Hasan ◽  
Braja Gopal Bag
Keyword(s):  
Gold Nanoparticles ◽  
Room Temperature ◽  
Antioxidant Property ◽  
Resonance Spectroscopy ◽  
Surface Plasmon Resonance Spectroscopy ◽  
Dpph Radical ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ftir Studies ◽  
Transmission Electron

The antioxidant activity of the endosperm extract of Borassus flabellifer (commonly known as Taal) has been studied against a long lived 2,2-diphenylpicrylhydrazyl (DPPH) radical at room temperature. The phytochemicals present in the endosperm extract have been utilized for the synthesis of stable gold nanoparticles at room temperature under very mild conditions. The synthesized gold nanoparticles were characterized by Surface Plasmon Resonance spectroscopy, High resolution transmission electron microscopy, X-Ray diffraction and FTIR studies and a mechanism for the synthesis of stabilized gold nanoparticles has been proposed.

Highly Luminescent Inverted ZnS/CdS Core/Shell Quantum Dots

2008 ◽  
Vol 8 (8) ◽  
pp. 3949-3954 ◽  
Author(s):  
Madhulika Sharma ◽  
D. Gupta ◽  
D. Kaushik ◽  
A. B. Sharma ◽  
R. K. Pandey
Keyword(s):  
Quantum Dots ◽  
Grazing Angle ◽  
Surface States ◽  
Shell Structures ◽  
Luminescence Spectroscopy ◽  
Core Shell ◽  
Additional Parameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

Synthesis of highly luminescent and monochromatic inverted core–shell structures utilizing ZnS/CdS quantum dots (QDs) has been investigated. The core/shell quantum dots have been characterized using grazing angle X-ray diffraction (XRD), Transmission electron microscopy, Optical absorption and luminescence spectroscopy. The results suggested that passivation of surface states along with an increased localization of electron and hole in CdS shell layer, give rise to increased monochromaticity with higher quantum yield. The possibility of using the inverted core–shell structure as an additional parameter for tuning the color of luminescence has also been discussed.

scholarly journals Optical and Thermoelectric Properties of Surface-Oxidation Sensitive Layered Zirconium Dichalcogenides ZrS2−xSex (x = 0, 1, 2) Crystals Grown by Chemical Vapor Transport

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 327
Author(s):  
Thalita Maysha Herninda ◽  
Ching-Hwa Ho
Keyword(s):  
Single Crystals ◽  
Thermoelectric Properties ◽  
Surface States ◽  
Chemical Vapor ◽  
Surface Oxidation ◽  
Vapor Transport ◽  
Chemical Vapor Transport ◽  
X Ray ◽  
Transmission Electron ◽  
Work Structure

In this work, structure, optical, and thermoelectric properties of layered ZrS2−xSex single crystals with selenium composition of x = 0, 1, and 2 were examined. Single crystals of zirconium dichalcogenides layer compounds were grown by chemical vapor transport method using I2 as the transport agent. X-ray diffraction (XRD) and high-resolution transmission electron microscope (HRTEM) results indicated that ZrS2−xSex (x = 0, 1, and 2) were crystalized in hexagonal CdI2 structure with one-layer trigonal (1T) stacking type. X-ray photoelectron and energy dispersive X-ray measurements revealed oxidation sensitive behavior of the chalcogenides series. Transmittance and optical absorption showed an indirect optical gap of about 1.78 eV, 1.32 eV, and 1.12 eV for the ZrS2−xSex with x = 0, 1, and 2, respectively. From the result of thermoelectric experiment, ZrSe2 owns the highest figure-of merit (ZT) of ~0.085 among the surface-oxidized ZrS2−xSex series layer crystals at 300 K. The ZT values of the ZrS2−xSex (x = 0, 1, and 2) series also reveal increase with the increase of Se content owing to the increase of carrier concentration and mobility in the highly Se-incorporated zirconium dichalcogenides with surface states.

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