Facile aqueous synthesis of functionalized CdTe nanoparticles and their application as fluorescence probes for determination of adenine and guanine

2012 ◽  
Vol 90 (2) ◽  
pp. 173-179 ◽  
Author(s):  
Li Li ◽  
Yaxiang Lu ◽  
Yaping Ding ◽  
Fenfen Zhang ◽  
Yaping Wang
Keyword(s):  
Dynamic Range ◽  
Fluorescence Emission ◽  
Fluorescence Probes ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Aqueous Synthesis ◽  
Cdte Nanoparticles ◽  
Transmission Electron ◽  
Quantitative Analysis Method

Thioglycolic acid (TGA)-capped CdTe nanoparticles (NPs) were synthesized in aqueous medium, and their application as fluorescence probes in the detection of adenine and guanine was studied. The TGA-capped CdTe NPs were characterized by transmission electron microscopy, X–ray diffraction spectrometry, spectrofluorometry, Fourier transform infrared, and ultraviolet-visible spectrometry. Based on the significant enhancement of fluorescence emission of these CdTe fluorescence probes in the presence of adenine or guanine, a quantitative analysis method for these purines was proposed. Experimental conditions that govern the extent of fluorescence enhancement were optimized. Under the optimal conditions, the relative fluorescence intensity versus adenine or guanine concentrations gave a linear response, permitting the dynamic range of 7.0 × 10−7–1.0 × 10−4 mol/L and 6.0 × 10−7–9.0 × 10−5 mol/L for adenine and guanine, respectively. The method has also been applied successfully to the detection of adenine and guanine in synthetic samples with satisfactory results.

Aqueous Processing of L-Glutathione Capped ZnO Quantum dots for Potential Biomedical Applications

2015 ◽  
Vol 1797 ◽  
Author(s):  
Raquel Feliciano-Crespo ◽  
José A Rodriguez ◽  
Myrna Reyes-Blas ◽  
Chuan-Jian Zhong ◽  
Oscar Perales-Perez
Keyword(s):  
Zno Nanoparticles ◽  
Cellular Membrane ◽  
Water Soluble ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Aqueous Synthesis ◽  
E Coli ◽  
Molar Ratios ◽  
Transmission Electron ◽  
Ft Ir

ABSTRACTMedical research has demonstrated the importance of the utilization of stable, fluorescent nanoprobes. The present work addresses the applicability of biocompatible and fluorescent ZnO nanoparticles as probes for detection of pathogens with the aim of achieving extremely low detection limits. For this purpose, ZnO surface must be functionalized for its subsequent interaction with bacterial cellular membrane (coupling), which will allow the corresponding detection and quantification. Herein we will discuss the aqueous synthesis of stable, water soluble and biologically compatible ZnO nanoparticles (NPss) capped with L-glutathione (GSH). The understanding of the interactions between GSH molecules and surface atoms in ZnO QDs became critical to foster the applicability of this nanomaterial in the biomedical and bioengineering fields. In this regard, the GSH/ZnO molar ratios, reaction temperature (40°C and 60°C), time and pH (6-9) became crucial factors to attain suitable tuning of the QDs properties. ZnO/GSH synthesized QDs were characterized by Transmission Electron Microscopy, X-Ray Diffraction, FT-IR, UV-Vis and photoluminescence (PL) spectroscopy. The QDs shape was spherical with a particle size between 80-100nm. The synthesis of ZnO/GSH under different experimental conditions and the corresponding coupling with E. Coli species, are presented and discussed.

Quantitative determination of uric acid using CdTe nanoparticles as fluorescence probes

2016 ◽  
Vol 77 ◽  
pp. 359-365 ◽  
Author(s):  
Dongri Jin ◽  
Min-Ho Seo ◽  
Bui The Huy ◽  
Quoc-Thai Pham ◽  
Maxwell L. Conte ◽  
...  
Keyword(s):  
Uric Acid ◽  
Quantitative Determination ◽  
Fluorescence Probes ◽  
Cdte Nanoparticles

scholarly journals Fabrication of a Food Nano-Platform Sensor for Determination of Vanillin in Food Samples

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2817 ◽  
Author(s):  
Vinod Gupta ◽  
Hassan Karimi-Maleh ◽  
Shilpi Agarwal ◽  
Fatemeh Karimi ◽  
Majede Bijad ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Food Samples ◽  
Precipitation Method ◽  
Single Wall Carbon Nanotubes ◽  
Modified Carbon Paste Electrode ◽  
Carbon Paste ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Paste Electrode

Herein, we describe the fabrication of NiO decorated single wall carbon nanotubes (NiO-SWCNTs) nanocomposites using the precipitation method. The synthesized NiO-SWCNTs nanocomposites were characterized by X-ray diffraction (XRD) and Transmission electron microscopy (TEM). Remarkably, NiO-SWCNTs and 1-butylpyridinium hexafluorophosphate modified carbon paste electrode (CPE/NiO-SWCNTs/BPrPF6) were employed for the electrochemical detection of vanillin. The vanillin sensor showed an ultra-high sensitivity of 0.3594 μA/μM and a low detection limit of 0.007 μM. In the final step, the NiO-SWCNTs/BPrPF6 was used as the suitable tool for food analysis.

scholarly journals Effect of Tetramethylammonium Hydroxide on Nucleation, Surface Modification and Growth of Magnetic Nanoparticles

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Ângela L. Andrade ◽  
José D. Fabris ◽  
José D. Ardisson ◽  
Manuel A. Valente ◽  
José M. F. Ferreira
Keyword(s):  
Zeta Potential ◽  
Magnetite Nanoparticles ◽  
Heat Dissipation ◽  
Tetramethylammonium Hydroxide ◽  
Precipitation Method ◽  
Attenuated Total Reflectance ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Transmission Electron ◽  
Magnetite Particles

Nanoparticles of magnetite (Fe3O4) were obtained by reacting ferric chloride with sodium sulphite, through the reduction-precipitation method. The effects of adding tetramethylammonium hydroxide (TMAOH) during or after the precipitation of the iron oxide were studied in an attempt to obtain well-dispersed magnetite nanoparticles. Accordingly, the following experimental conditions were tested: (i) precipitation in absence of TMAOH (sample Mt), (ii) the same as (i) after peptizing with TMAOH (Mt1), (iii) TMAOH added to the reaction mixture during the precipitation of magnetite (Mt2). Analyses with transmission electron microscopy (TEM), X-ray diffraction, Mössbauer spectroscopy, attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), zeta potential, and magnetization measurements up to 2.5 T revealed that magnetite was normally formed also in the medium containing TMAOH. The degree of particles agglomeration was monitored with laser diffraction and technique and inspection of TEM images. The relative contributions of Néel and Brownian relaxations on the magnetic heat dissipation were studied by investigating the ability of suspensions of these magnetite nanoparticles to release heat in aqueous and in hydrogel media. Based on ATR-FTIR and zeta potential data, it is suggested that the surfaces of the synthesized magnetite particles treated with TMAOH become coated with (CH3)4N+cations.

scholarly journals Biomass-Derived Activated Carbon as a Catalyst for the Effective Degradation of Rhodamine B dye

Processes ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 926
Author(s):  
Shamim Ahmed Hira ◽  
Mohammad Yusuf ◽  
Dicky Annas ◽  
Hu Shi Hui ◽  
Kang Hyun Park
Keyword(s):  
Electron Microscopy ◽  
Activated Carbon ◽  
Rhodamine B ◽  
Photoelectron Spectroscopy ◽  
High Specific Surface Area ◽  
High Porosity ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
X Ray ◽  
Transmission Electron

Activated carbon (AC) was fabricated from carrot waste using ZnCl2 as the activating agent and calcined at 700 °C for 2 h in a tube furnace. The as-synthesized AC was characterized using Fourier-transform infrared spectroscopy, X-ray diffraction analysis, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and Brunauer–Emmett–Teller analysis; the results revealed that it exhibited a high specific surface area and high porosity. Moreover, this material displayed superior catalytic activity for the degradation of toxic Rhodamine B (RhB) dye. Rate constant for the degradation of RhB was ascertained at different experimental conditions. Lastly, we used the Arrhenius equation and determined that the activation energy for the decomposition of RhB using AC was approximately 35.9 kJ mol−1, which was very low. Hopefully it will create a great platform for the degradation of other toxic dye in near future.

scholarly journals Novel Nanohybrids Based on Supramolecular Assemblies of Meso-tetrakis-(4-sulfonatophenyl) Porphyrin J-aggregates and Amine-Functionalized Carbon Nanotubes

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 669 ◽  
Author(s):  
Mariachiara Trapani ◽  
Antonino Mazzaglia ◽  
Anna Piperno ◽  
Annalaura Cordaro ◽  
Roberto Zagami ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Transmission Electron Microscopy ◽  
Fluorescence Emission ◽  
Resonance Light Scattering ◽  
Therapeutic Window ◽  
Multiwalled Carbon ◽  
Experimental Conditions ◽  
Transmission Electron ◽  
J Aggregates

The ability of multiwalled carbon nanotubes (MWCNTs) covalently functionalized with polyamine chains of different length (ethylenediamine, EDA and tetraethylenepentamine, EPA) to induce the J-aggregation of meso-tetrakis(4-sulfonatophenyl)porphyrin (TPPS) was investigated in different experimental conditions. Under mild acidic conditions, protonated amino groups allow for the assembly by electrostatic interaction with the diacid form of TPPS, leading to hybrid nanomaterials. The presence of only one pendant amino group for a chain in EDA does not lead to any aggregation, whereas EPA (with four amine groups for chain) is effective in inducing J-aggregation using different mixing protocols. These nanohybrids have been characterized through UV/Vis extinction, fluorescence emission, resonance light scattering and circular dichroism spectroscopy. Their morphology and chemical composition have been elucidated through transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM). TEM and STEM analysis evidence single or bundles of MWCNTs in contact with TPPS J-aggregates nanotubes. The nanohybrids are quite stable for days, even in aqueous solutions mimicking physiological medium (NaCl 0.15 M). This property, together with their peculiar optical features in the therapeutic window of visible spectrum, make them potentially useful for biomedical applications.

Use of the curvature method to determine the misfit stress of epitaxial semiconducting systems: the case of samples thinned for TEM observation.

2003 ◽  
Vol 795 ◽  
Author(s):  
A. Ponchet ◽  
M. Cabié ◽  
L. Durand ◽  
M. Rivoal ◽  
A. Rocher
Keyword(s):  
Electron Microscopy ◽  
Mechanical Characteristics ◽  
Substrate Thickness ◽  
Element Calculation ◽  
Experimental Conditions ◽  
Misfit Stress ◽  
Reliable Determination ◽  
Substrate Side ◽  
Transmission Electron

ABSTRACTThe curvature method which allows to measure the stress in epitaxial layers has been adapted to transmission electron microscopy observations. The samples thinned by the substrate side present some particular mechanical characteristics. The ratio between the substrate thickness and the layer thickness should be taken into account. The experimental conditions allowing a reliable determination of the stress have been established. A finite element calculation has been used to show that the dimensions of the area where the measure is performed can not systematically be neglected. This method has been applied to the semiconducting systems Ga1-xInxAs/GaAs and Ga1-xInxAs/InP.

scholarly journals Tumoricidal and Bactericidal Properties of ZnONPs Synthesized Using Cassia auriculata Leaf Extract

Biomolecules ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 982 ◽  
Author(s):  
Kollur Shiva Prasad ◽  
Shashanka K. Prasad ◽  
Mohammad Azam Ansari ◽  
Mohammad A. Alzohairy ◽  
Mohammad N. Alomary ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fluorescence Emission ◽  
Fluorescence Emission Spectrum ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Cassia Auriculata ◽  
Transmission Electron ◽  
Normal Human Breast

In this work, we aimed to synthesize zinc oxide nanoparticles (ZnONPs) using an aqueous extract of Cassia auriculata leaves (CAE) at room temperature without the provision of additional surfactants or capping agents. The formation of as-obtained ZnONPs was analyzed by UV–visible (ultraviolet) absorption and emission spectroscopy, X-ray photoemission spectroscopy (XPS), X-ray diffraction analysis (XRD), energy dispersive X-ray diffraction (EDX), thermogravimetric analysis/differential thermal analysis (TGA-DTA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and selected area electron diffraction (SAED). The XRD results reflect the wurtzite structure of as-prepared ZnONPs, which produced diffraction patterns showing hexagonal phases. The SEM images indicate that the morphology of as-prepared ZnONPs is composed of hexagonal nanostructures with an average diameter of 20 nm. The HR-TEM result shows that the inter-planar distance between two lattice fringes is 0.260 nm, which coincides with the distance between the adjacent (d-spacing) of the (002) lattice plane of ZnO. The fluorescence emission spectrum of ZnONPs dispersed in ethanol shows an emission maximum at 569 nm, revealing the semiconductor nature of ZnO. As-obtained ZnONPs enhanced the tumoricidal property of CAE in MCF-7 breast cancer cells without significant inhibition of normal human breast cells, MCF-12A. Furthermore, we have studied the antibacterial effects of ZnONPs, which showed direct cell surface contact, resulting in the disturbance of bacterial cell integrity.

Laccase Biosensor Based on Ag-Doped TiO2 Nanoparticles on CuCNFs for the Determination of Hydroquinone

NANO ◽  
2016 ◽  
Vol 11 (12) ◽  
pp. 1650132 ◽  
Author(s):  
Jie Yang ◽  
Dawei Li ◽  
Zengyuan Pang ◽  
Qufu Wei
Keyword(s):  
Electron Microscopy ◽  
Storage Stability ◽  
Electrochemical Impedance ◽  
The Novel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
New Material ◽  
And Storage

A novel nanomaterial composed of copper and carbon nanofibers (CuCNFs) decorated with Ag-doped TiO2 (Ag–TiO[Formula: see text] nanoparticles was prepared through electrospinning, carbonization and solvothermal treatment. The composites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and electrochemical impedance spectroscopy (EIS). The obtained composites were mixed with laccase and Nafion to construct novel hydroquinone biosensor. The electrochemical behavior of the novel biosensor was studied using cyclic voltammetry (CV) and chronoamperometry. The results demonstrated that the biosensor possessed a wide detection linear range (1.20–176.50[Formula: see text][Formula: see text]M), a good selectivity, repeatability, reproducibility and storage stability. This work provides a new material to design more efficient laccase (Lac) based biosensor for hydroquinone detection.

Controllable one-step synthesis of ZnO nanostructures using molybdophosphoric acid

2014 ◽  
Vol 68 (4) ◽  
Author(s):  
Hamed Rashidi ◽  
Ali Ahmadpour ◽  
Fatemeh Bamoharram ◽  
Seyed Zebarjad ◽  
Majid Heravi ◽  
...  
Keyword(s):  
Photocatalytic Degradation ◽  
High Performance ◽  
Hydrothermal Reaction ◽  
Hexagonal Phase ◽  
Zno Nanostructures ◽  
Molybdophosphoric Acid ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Transmission Electron ◽  
One Step

AbstractZnO nanostructures were synthesised in a hydrothermal reaction of zinc acetate in the presence of molybdophosphoric acid (H3[PMo12O40]) as well as its vanadium-substituted acid (H4[PMo11VO40]) at various times, temperatures, and concentrations. The ZnO nanostructures were characterised by X-ray diffraction, transmission electron microscopy, and Fourier transform infrared spectroscopy. The results demonstrated that the synthesised products are crystalline with a zincite hexagonal phase. Various ZnO nanostructures, such as nanoparticles, microrods, and nanosheets, were produced by changing the experimental conditions. The photocatalytic degradation of methyl orange was also investigated using the ZnO nanoparticles thus prepared. These particles exhibited high performance in the photocatalytic degradation of MO and almost 100 % decolourisation occurred within only 20 min.

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