scholarly journals Single-Walled Carbon Nanotubes (SWCNTs) as Solid-Contact in All-Solid-State Perchlorate ISEs: Applications to Fireworks and Propellants Analysis

Sensors ◽  
2019 ◽  
Vol 19 (12) ◽  
pp. 2697 ◽  
Author(s):  
Saad S. M. Hassan ◽  
Ahmed Galal Eldin ◽  
Abd El-Galil E. Amr ◽  
Mohamed A. Al-Omar ◽  
Ayman H. Kamel
Keyword(s):  
Carbon Nanotubes ◽  
Electrochemical Impedance ◽  
Cost Effective ◽  
Single Walled Carbon Nanotubes ◽  
Solid Contact ◽  
Single Walled Carbon ◽  
Tetraphenyl Porphyrin ◽  
Eis Measurements ◽  
Walled Carbon Nanotubes ◽  
Potential Stability

Herein, we present reliable, robust, stable, and cost-effective solid-contact ion-selective electrodes (ISEs) for perchlorate determination. Single-walled carbon nanotubes (SWCNTs) were used as solid-contact material and indium (III) 5, 10, 15, 20-(tetraphenyl) porphyrin chloride (InIII-porph) as an ion carrier. The sensor exhibited an improved sensitivity towards ClO4− ions with anionic slope of −56.0 ± 1.1 (R2 = 0.9998) mV/decade over a linear range 1.07 × 10−6 – 1.0 × 10−2 M and detection limit of 1.8 × 10−7 M. The short-term potential stability and the double-layer capacitance were measured by chronopotentiometric and electrochemical impedance spectroscopy (EIS) measurements, respectively. The sensor is used for ClO4− determination in fireworks and propellant powders. The results fairly agree with data obtained by ion chromatography.

scholarly journals Negatively-Doped Single-Walled Carbon Nanotubes Decorated with Carbon Dots for Highly Selective NO2 Detection

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2509
Author(s):  
Namsoo Lim ◽  
Jae-Sung Lee ◽  
Young Tae Byun
Keyword(s):  
Carbon Nanotubes ◽  
Gas Sensors ◽  
Cost Effective ◽  
Single Walled Carbon Nanotubes ◽  
X Ray Diffraction ◽  
Single Walled Carbon ◽  
Sensor Applications ◽  
Transmission Electron ◽  
P Type ◽  
Walled Carbon Nanotubes

In this study, we demonstrated a highly selective chemiresistive-type NO2 gas sensor using facilely prepared carbon dot (CD)-decorated single-walled carbon nanotubes (SWCNTs). The CD-decorated SWCNT suspension was characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), and UV-visible spectroscopy, and then spread onto an SiO2/Si substrate by a simple and cost-effective spray-printing method. Interestingly, the resistance of our sensor increased upon exposure to NO2 gas, which was contrary to findings previously reported for SWCNT-based NO2 gas sensors. This is because SWCNTs are strongly doped by the electron-rich CDs to change the polarity from p-type to n-type. In addition, the CDs to SWCNTs ratio in the active suspension was critical in determining the response values of gas sensors; here, the 2:1 device showed the highest value of 42.0% in a sensing test using 4.5 ppm NO2 gas. Furthermore, the sensor selectively responded to NO2 gas (response ~15%), and to other gases very faintly (NO, response ~1%) or not at all (CO, C6H6, and C7H8). We propose a reasonable mechanism of the CD-decorated SWCNT-based sensor for NO2 sensing, and expect that our results can be combined with those of other researches to improve various device performances, as well as for NO2 sensor applications.

Nanostructured cobalt phthalocyanine single-walled carbon nanotube platform: electron transport and electrocatalytic activity on epinephrine

2008 ◽  
Vol 12 (12) ◽  
pp. 1289-1299 ◽  
Author(s):  
Bolade O. Agboola ◽  
Alfred Mocheko ◽  
Jeseelan Pillay ◽  
Kenneth I. Ozoemena
Keyword(s):  
Carbon Nanotubes ◽  
Electrocatalytic Activity ◽  
Electrochemical Impedance ◽  
Limit Of Detection ◽  
Pyrolytic Graphite ◽  
Single Walled Carbon Nanotubes ◽  
Cobalt Phthalocyanine ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes

The fabrication, characterization and application of edge-plane pyrolytic graphite electrode modified with acid-functionalized single-walled carbon nanotubes, nanostructured cobalt phthalocyanine and a mixture of both, towards epinephrine detection and analysis are described. The morphological features of the films were evaluated using atomic force microscopy (AFM). Electrochemistry of these electrodes in [ Fe ( CN )6]3−/4− using cyclic voltammetry and electrochemical impedance spectroscopy showed higher peak current responses with accompanying low electron-transfer resistances in comparison to the bare electrode. The edge-plane pyrolytic graphite-single-walled carbon nanotubes-nanostructured cobalt phthalocyanine electrode exhibited good electrocatalytic activity towards epinephrine oxidation with enhanced peak currents. Analytical studies using edge-plane pyrolytic graphite-single-walled carbon nanotubes-nanostructured cobalt phthalocyanine electrode proved that the electrode is suitable for sensitivity determination of epinephrine in pH 5 conditions judging from the good sensitivity (8.71 ± 0.31 A.M−1), and limit of detection (0.04 µM) and quantification (1.31 µM) obtained. Determination of EP in the absence and presence of ascorbic acid in phosphate buffer pH 5 conditions was carried out and it was established that the presence of AA did not interfere in EP analysis. Rotating disk electrode experiments proved that the catalytic rate constant was 2.28 × 1016 mM−1.s−1.

Green silver nanobioarchitectures with amplified antioxidant and antimicrobial properties

2014 ◽  
Vol 2 (21) ◽  
pp. 3221-3231 ◽  
Author(s):  
Marcela Elisabeta Barbinta-Patrascu ◽  
Camelia Ungureanu ◽  
Stefan Marian Iordache ◽  
Ioana Raluca Bunghez ◽  
Nicoleta Badea ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Antimicrobial Properties ◽  
Cost Effective ◽  
Single Walled Carbon Nanotubes ◽  
Bottom Up ◽  
Single Walled Carbon ◽  
Biomimetic Membranes ◽  
Walled Carbon Nanotubes

A novel, simple and cost-effective bottom-up approach was developed to achieve antioxidant and antimicrobial biohybrids based on biomimetic membranes, phyto-nanosilver and single-walled carbon nanotubes.

scholarly journals Protein Detection with Potentiometric Aptasensors: A Comparative Study between Polyaniline and Single-Walled Carbon Nanotubes Transducers

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Ali Düzgün ◽  
Hassan Imran ◽  
Kalle Levon ◽  
F. Xavier Rius
Keyword(s):  
Carbon Nanotubes ◽  
Surface Characterization ◽  
Electrochemical Impedance ◽  
Protein Detection ◽  
Single Walled Carbon Nanotubes ◽  
Comparison Study ◽  
Single Walled Carbon ◽  
Multiply Charged ◽  
Walled Carbon Nanotubes

A comparison study on the performance characteristics and surface characterization of two different solid-contact selective potentiometric thrombin aptasensors, one exploiting a network of single-walled carbon nanotubes (SWCNTs) and the other the polyaniline (PANI), both acting as a transducing element, is described in this work. The molecular properties of both SWCNT and PANI surfaces have been modified by covalently linking thrombin binding aptamers as biorecognition elements. The two aptasensors are compared and characterized through potentiometry and electrochemical impedance spectroscopy (EIS) based on the voltammetric response of multiply charged transition metal cations (such as hexaammineruthenium, [Ru(NH3)6]3+) bound electrostatically to the DNA probes. The surface densities of aptamers were accurately determined by the integration of the peak for the reduction of [Ru(NH3)6]3+to [Ru(NH3)6]2+. The differences and the similarities, as well as the transduction mechanism, are also discussed. The sensitivity is calculated as 2.97 mV/decade and 8.03 mV/decade for the PANI and SWCNTs aptasensors, respectively. These results are in accordance with the higher surface density of the aptamers in the SWCNT potentiometric sensor.

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