A Label-Free Electrochemical Aptasensor for the Rapid Detection of Tetracycline Based on Ordered Mesoporous Carbon–Fe3O4

2018 ◽  
Vol 71 (3) ◽  
pp. 170 ◽  
Author(s):  
Xuejia Zhan ◽  
Guangzhi Hu ◽  
Thomas Wagberg ◽  
Dongwei Zhang ◽  
Pei Zhou
Keyword(s):  
Photoelectron Spectroscopy ◽  
Mesoporous Carbon ◽  
Physical Adsorption ◽  
Differential Pulse ◽  
Ordered Mesoporous Carbon ◽  
Label Free ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ordered Mesoporous ◽  
Modification Procedure

A novel aptasensor based on a tetracycline (TET) aptamer immobilized by physical adsorption on an ordered mesoporous carbon–Fe3O4 (OMC-Fe3O4)-modified screen-printed electrode surface was successfully fabricated. OMC-Fe3O4 was characterized by scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The modification procedure of the aptasensor was characterized by cyclic voltammetry. Interaction between the TET aptamer and target was determined by differential pulse voltammetry. Under optimal conditions, the proposed aptasensor exhibited good electrochemical sensitivity to TET in a concentration range of 5 nM to 10 μM, with a detection limit of 0.8 nM (S/N = 3). This aptasensor exhibited satisfactory specificity, reproducibility, and stability.

Synthesis, Characterization and Physiochemical Properties of Platinum Supported on Mesoporous Carbon

2011 ◽  
Author(s):  
Salam J. J. Titinchi ◽  
Waheed Saban ◽  
Leslie Petrik ◽  
Hanna S. Abbo
Keyword(s):  
Surface Area ◽  
Pore Volume ◽  
Mesoporous Carbon ◽  
Chemical Vapour ◽  
Nitrogen Adsorption ◽  
Ordered Mesoporous Carbon ◽  
Pt Catalyst ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ordered Mesoporous

Ordered mesoporous carbon (OMC) has been prepared by impregnating the pores of the silica template (SBA-15) with liquid petroleum gas (LPG) or sucrose. The desired support (OMC) was obtained after dissolution with NaOH. Platinum nanoparticles were dispersed on ordered mesoporous carbons using Chemical Vapour Deposition (CVD) method and Pt(acac)2 as metal source. The resulting ordered mesoporous carbon possess a large surface area with high microporosity, and a controlled pore size distribution, High-quality carbon replicas of SBA-15 show an X-ray diffraction peak at low angle, which indicates that the structural periodicity of the (111) planes has been maintained. Their pore volume and specific surface area are high and the pore volume is almost entirely microporous. The synthesized Pt/OMC was characterized by powder X-Ray diffraction, HR-TEM, HR-SEM, EDS, thermogravimetric analysis, and nitrogen adsorption. The performance of Pt catalyst supported OMC was evaluated by electrochemical studies, which shows almost similar activity to the commercial catalyst.

scholarly journals Ordered Mesoporous Carbon as a Support for Palladium-Based Hydrodechlorination Catalysts

Catalysts ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 23
Author(s):  
Farzeen Sakina ◽  
Carlos Fernandez-Ruiz ◽  
Jorge Bedia ◽  
Luisa Gomez-Sainero ◽  
Richard Baker
Keyword(s):  
Photoelectron Spectroscopy ◽  
Mesoporous Carbon ◽  
Catalyst Deactivation ◽  
Average Diameter ◽  
Pd Nanoparticles ◽  
Ordered Mesoporous Carbon ◽  
Catalyst Composition ◽  
Ordered Mesoporous ◽  
Higher Hydrocarbons ◽  
Carbon Catalysts

Ordered mesoporous carbon (OMC) was employed as a support for palladium nanoparticles in catalysts for the gas phase hydrodechlorination (HDC) of trichloromethane (TCM). 1 wt% palladium was incorporated using three methods: incipient wetness (IW); a dilute solution (DS) method; and a solid-liquid (SL) method. The effect of the preparation method on catalyst structure and activity was investigated. Catalyst composition and nanostructure were studied using gas physisorption, high specification transmission electron microscopy and X-ray photoelectron spectroscopy. Catalytic conversion and product selectivities were determined in steady-state activity tests at temperatures between 70 and 300 °C. Two of the catalysts (IW and DS) showed excellent dispersion of fine Pd nanoparticles of average diameter ~2 nm. These materials showed excellent activity for HDC of TCM which compares favourably with the performance reported for Pd on amorphous carbon catalysts. In addition, they showed relatively high selectivities to the more valuable higher hydrocarbons. However, the SL method gave rise to catalysts with larger particles (~3 nm) and a less uniform palladium distribution. This resulted in lower conversion and lower selectivities to higher hydrocarbons and in more severe catalyst deactivation at the highest reaction temperatures.

scholarly journals Adsorption characteristics of ciprofloxacin on the schorl: kinetics, thermodynamics, effect of metal ion and mechanisms

2017 ◽  
Vol 8 (3) ◽  
pp. 350-359 ◽  
Author(s):  
Danyang Yin ◽  
Zhengwen Xu ◽  
Jing Shi ◽  
Lili Shen ◽  
Zexiang He
Keyword(s):  
Photoelectron Spectroscopy ◽  
Metal Ion ◽  
Adsorption Process ◽  
Ph Value ◽  
Physical Adsorption ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
X Ray ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Abstract In this study, schorl was used as an effective adsorbent for ciprofloxacin removal from wastewater. The adsorption performance, mechanism and effect of metal ion on sorption were investigated. Adsorption capacity reached a maximum (8.49 mg/g) when the pH value was 5.5. The pseudo-second-order kinetic model and Freundlich model could better describe the experimental data. The negative ΔH (–22.96 KJ/mol) value showed that the adsorption process was exothermic. The results also indicated physical adsorption existed on the adsorption process, which was in agreement with the analysis of X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy. The desorption rate could reach 94%, which suggested that schorl had a good desorption and regeneration performance. Coexisting ions, such as Cu2+ and Al3+, could obviously inhibit adsorption, and the inhibition from Al3+ was significantly higher than that from Cu2+. However, the additional Zn2+ could slightly promote the adsorption.

Enhanced Capacitance of Microwave-assisted Functionalized Ordered Mesopourous Carbon for Supercapacitors

2012 ◽  
Vol 15 (3) ◽  
pp. 203-209 ◽  
Author(s):  
B. Portales-Martínez ◽  
R.G. González-Huerta ◽  
J.M. Domínguez-Esquivel ◽  
C.A. Cortés-Escobedo
Keyword(s):  
Photoelectron Spectroscopy ◽  
Mesoporous Carbon ◽  
Nitrogen Adsorption ◽  
Electrochemical Capacitance ◽  
X Ray ◽  
Molding Method ◽  
Microwave Assisted ◽  
Transmission Electron ◽  
Ordered Mesoporous ◽  
Adsorption Desorption

The electrochemical capacitance for a double layer of ordered mesoporous carbon (OMC) nanofibers functionalized under differing conditions is presented. OMC nanofibers were prepared using the molding method from SBA-15 and sucrose. Functionalisation was performed using varying HNO3 concentrations at 110°C and 120°C assisted by microwave radiation over 3 minutes. The transmission electron micrographs of the resulting fibers are reported. The capacitance, surface area and functional groups as functions of the acidity and heat treatment were analysed via cyclic voltammetry, nitrogen adsorption-desorption, and X-ray photoelectron spectroscopy, respectively. Ordered nanofibers treated with 7.7 M HNO3 at 110°C exhibited the highest capacitance.

Marked Enhancement of Photocatalytic Activity of P-Doped TiO2 with Hydrothermal Method

2010 ◽  
Vol 113-116 ◽  
pp. 2150-2153 ◽  
Author(s):  
Si Yao Guo ◽  
Feng Lu Wang ◽  
Jin Bing Sun ◽  
Lin Yang ◽  
Feng Zhang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Hydrothermal Method ◽  
Photoelectron Spectroscopy ◽  
Physical Adsorption ◽  
Anatase Phase ◽  
Titania Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
One Step ◽  
Doped Titania

Phosphor-doped titania nanoparticles were synthesized by a one step hydrothermal method. These samples which prepared by hydrothermal method exist in anatase phase has much higher photocatalytic activity for methylene blue (MB) degradation. In addition, MB degradation performance of the hydrothermal ones is also superior to that of the commercial P25. The resulting materials were characterized by X-ray diffraction (XRD), nitrogen physical adsorption at 77 K, X-ray photoelectron spectroscopy (XPS), etc. It can conclude the hydrothermal method proves to be more suitable to improve the photocatalytic performance.

Facile Fabrication of Magnetic Nanocomposites of Ordered Mesoporous Carbon Decorated with Nickel Nanoparticles

2007 ◽  
Vol 7 (2) ◽  
pp. 504-509 ◽  
Author(s):  
Yulin Cao ◽  
Jieming Cao ◽  
Mingbo Zheng ◽  
Jinsong Liu ◽  
Guangbin Ji ◽  
...  
Keyword(s):  
Mesoporous Carbon ◽  
Nickel Nanoparticles ◽  
Hysteresis Loops ◽  
Ordered Mesoporous Carbon ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Ordered Mesoporous ◽  
Special Surface ◽  
Facile Fabrication

A magnetic nanocomposite of ordered mesoporous carbon (CMK-3) decorated with nickel nanoparticles was synthesized successfully by a simple chemistry method. Nickel nanoparticles were prepared and uniformly supported on ordered mesoporous carbon CMK-3 by reduction route with CMK-3 as a reducing agent at 673 K. The Ni/CMK-3 composite materials were characterized by powder X-ray diffraction, nitrogen sorption, and transmission electron microscopy. As-prepared nickel nanoparticles supported on CMK-3 were crystalline with a face-center-cubic phase and a size distribution ranging from 10 to 60 nm. The BET special surface area and pore volume of Ni/CMK-3 were as high as 797 m2 g−1 and 0.72 cm3 g−1, respectively. The formation mechanism of the nickel nanoparticles outside the surface of CMK-3 was preliminarily discussed. The hysteresis loops of the CMK-3 decorated with nickel nanoparticles were measured by vibrating sample magnetometer (VSM), and the results showed that the composite was ferromagnetism with the saturated magnetization of 15 emu/g, and the coercivity value of 214 Oe. Furthermore, the application of Ni/CMK-3 as magnetically separable adsorbent for vitamin B2 was primarily examined in this study.

Phosphorus Doped Titania Materials: Synthesis, Characterization and Visible-Light Photocatalytic Activity

2011 ◽  
Vol 183-185 ◽  
pp. 2059-2062 ◽  
Author(s):  
Song Han ◽  
Jin Bing Sun ◽  
Si Yao Guo ◽  
Li Jiang ◽  
Dong Po He
Keyword(s):  
Photocatalytic Activity ◽  
Hydrothermal Method ◽  
Photoelectron Spectroscopy ◽  
Physical Adsorption ◽  
Titania Nanoparticles ◽  
X Ray Diffraction ◽  
Materials Synthesis ◽  
X Ray ◽  
Titania Photocatalyst ◽  
Doped Titania

Hierarchical mesoporous Phosphor-doped titania nanoparticles were synthesized by two different method, that is roasting method and hydrothermal method. The samples prepared by hydrothermal method has much higher photocatalytic activity. In addition, MB degradation performance of the hydrothermal ones is also superior to that of the commercial P25. Therefore, the methylene blue (MB) degradation performance on the phosphorous-doped photocatalyst is much enhanced and superior to that of the commercial P25. The hydrothermal method proves to be very suitable for the synthesis of P-doped titania photocatalyst. The resulting materials were characterized by X-ray diffraction (XRD), nitrogen physical adsorption at 77 K, X-ray photoelectron spectroscopy (XPS), and solar light spectroscopy.

Investigation of the Effect of Uv-Assisted Oxidation and Nitridation of Hafnium Metal Films

2003 ◽  
Vol 780 ◽  
Author(s):  
C. Essary ◽  
V. Craciun ◽  
J. M. Howard ◽  
R. K. Singh
Keyword(s):  
Uv Radiation ◽  
Photoelectron Spectroscopy ◽  
Grazing Angle ◽  
X Ray Diffraction ◽  
Metal Thin Films ◽  
X Ray ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force ◽  
Silicon Interface

AbstractHf metal thin films were deposited on Si substrates using a pulsed laser deposition technique in vacuum and in ammonia ambients. The films were then oxidized at 400 °C in 300 Torr of O2. Half the samples were oxidized in the presence of ultraviolet (UV) radiation from a Hg lamp array. X-ray photoelectron spectroscopy, atomic force microscopy, and grazing angle X-ray diffraction were used to compare the crystallinity, roughness, and composition of the films. It has been found that UV radiation causes roughening of the films and also promotes crystallization at lower temperatures.Furthermore, increased silicon oxidation at the interface was noted with the UVirradiated samples and was shown to be in the form of a mixed layer using angle-resolved X-ray photoelectron spectroscopy. Incorporation of nitrogen into the film reduces the oxidation of the silicon interface.

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