A highly sensitive electrochemical aptasensor for thrombin detection using functionalized mesoporous silica@multiwalled carbon nanotubes as signal tags and DNAzyme signal amplification

The Analyst ◽  
2013 ◽  
Vol 138 (22) ◽  
pp. 6938 ◽  
Author(s):  
Juan Zhang ◽  
Yaqin Chai ◽  
Ruo Yuan ◽  
Yali Yuan ◽  
Lijuan Bai ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Mesoporous Silica ◽  
Multiwalled Carbon Nanotubes ◽  
Signal Amplification ◽  
Electrochemical Aptasensor ◽  
Multiwalled Carbon ◽  
Functionalized Mesoporous Silica ◽  
Highly Sensitive

SOLID-PHASE EXTRACTION OF PHTHALATE ESTERS FROM AQUEOUS SAMPLES USING MESOPOROUS SILICA-COATED MULTIWALLED CARBON NANOTUBES AND THEIR DETERMINATION BY HPLC

NANO ◽  
2014 ◽  
Vol 09 (04) ◽  
pp. 1450054 ◽  
Author(s):  
XIAOYING DENG ◽  
XIAOQING CHEN ◽  
XINYU JIANG
Keyword(s):  
Carbon Nanotubes ◽  
Mesoporous Silica ◽  
Solid Phase Extraction ◽  
Multiwalled Carbon Nanotubes ◽  
Solid Phase ◽  
Phthalate Esters ◽  
Phase Extraction ◽  
Aqueous Samples ◽  
Multiwalled Carbon ◽  
Relative Standard

We report a novel solid-phase extraction adsorbent for the preconcentration of three phthalate esters (PAEs) from aqueous samples. The material was obtained by modifying multiwalled carbon nanotubes (MWCNTs) with mesoporous silica. The structural characterization of the adsorbent was conducted by Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM) and N 2 adsorption–desorption measurement, which confirmed the successful coating of mesoporous silica on MWCNTs and the adsorbent possessing large surface and porous structure. The effects of adsorbent amount, type and volume of eluent and sample pH on extraction efficiency were optimized. Following extraction, the PAEs were quantified by high performance liquid chromatography (HPLC). Under optimal conditions, the recoveries ranged from 89.8% to 96.3%. The calibration plot was linear in the 3–1000 ng⋅mL-1 concentration range, with correlation coefficients ranging from 0.9993 to 0.9995. The repeatability of the method, expressed as relative standard deviation (RSD), ranged from 3.8% to 7.7% (for n = 5). Limits of detection (LODs) were between 0.28 ng mL-1 and 0.53 ng⋅mL-1. The relative recoveries (RR) for spiked river water, pond water and tap water samples were in the ranges of 80.9–98.0%, 82.7–96.1% and 88.3–95.5%, respectively. The results showed that the method obviously had a large potential for preconcentration and determination of PAEs in environmental samples.

Comparative in vivo toxicity assessment places multiwalled carbon nanotubes at a higher level than mesoporous silica nanoparticles

2016 ◽  
Vol 33 (2) ◽  
pp. 182-192 ◽  
Author(s):  
Nidhi Rawat ◽  
Sandhya ◽  
Kesavan Subaharan ◽  
M Eswaramoorthy ◽  
Gautam Kaul
Keyword(s):  
Carbon Nanotubes ◽  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
Multiwalled Carbon Nanotubes ◽  
Mesoporous Silica Nanoparticles ◽  
Treated Group ◽  
Cellular Level ◽  
Multiwalled Carbon ◽  
In Vivo Toxicity

In the present work, we took two nanomaterials (NMs), mesoporous silica nanoparticles (MSNs) and multiwalled carbon nanotubes (MWCNTs), and compared their in vivo toxicity taking albino mice as a test animal model. Presently, conflicting data persist regarding behavior of these NMs with macromolecules like protein and lipid at the cellular level in cell lines as well as in animal models and this generated the interest to study them. The mice were treated orally with a single dose of 50 ppm MWCNTs and intraperitoneally with 10, 25, and 50 mg kg−1 body weight (BW) of MSNs and 1.5, 2.0, and 2.5 mg kg−1 BW of MWCNTs. Liver enzyme markers serum aspartate aminotransferase (AST), alanine aminotransferase, and alkaline phosphatase along with total protein (TP) levels were evaluated 7 days postexposure. No significant differences in organ weight indices or enzyme levels were observed between different treatment doses but there were significant differences between the treatment groups and the controls. Of the three enzymes assayed, AST displayed a peculiar pattern, especially in the MWCNTs intraperitoneally treated group. TP level was significantly increased in the orally treated MWCNTs group. The results showed that MWCNTs even at much smaller doses than MSNs displayed similar toxicity levels, suggesting that toxicity of MWCNTs is greater than MSNs.

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