Electrochemical impedance biosensor array based on DNAzyme-functionalized single-walled carbon nanotubes using Gaussian process regression for Cu(II) and Hg(II) determination

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.

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

The Scientific World JOURNAL ◽

10.1155/2013/282756 ◽

2013 ◽

Vol 2013 ◽

pp. 1-8 ◽

Cited By ~ 5

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

Sensors ◽

10.3390/s19122697 ◽

2019 ◽

Vol 19 (12) ◽

pp. 2697 ◽

Cited By ~ 3

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.

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Direct DNA Hybridization on the Single-Walled Carbon Nanotubes Modified Sensors Detected by Voltammetry and Electrochemical Impedance Spectroscopy

Electroanalysis ◽

10.1002/elan.200904640 ◽

2009 ◽

Vol 21 (19) ◽

pp. 2116-2124 ◽

Cited By ~ 36

Author(s):

Ayfer Caliskan ◽

Arzum Erdem ◽

Hakan Karadeniz

Keyword(s):

Carbon Nanotubes ◽

Electrochemical Impedance Spectroscopy ◽

Impedance Spectroscopy ◽

Dna Hybridization ◽

Electrochemical Impedance ◽

Single Walled Carbon Nanotubes ◽

Single Walled Carbon ◽

Walled Carbon Nanotubes

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Strain–capacitance relationship in polymer actuators based on single-walled carbon nanotubes and ionic liquid gels

Faraday Discussions ◽

10.1039/c6fd00232c ◽

2017 ◽

Vol 199 ◽

pp. 405-422 ◽

Cited By ~ 2

Author(s):

Hyacinthe Randriamahazaka ◽

Kinji Asaka

Keyword(s):

Carbon Nanotubes ◽

Ionic Liquid ◽

Electrochemical Impedance ◽

Mechanical Energy ◽

Single Walled Carbon Nanotubes ◽

Electromechanical Properties ◽

Ionic Liquid Electrolyte ◽

Single Walled Carbon ◽

Walled Carbon Nanotubes ◽

Capacitance Coefficient

We investigate the electromechanical properties of bucky-gel electrochemical actuators incorporating various amounts of single-walled carbon nanotubes and an ionic liquid electrolyte, 1-butyl-3-methylimidazolium tetrafluoroborate, that are able to convert electrochemical energy into mechanical energy. The interplay between mechanical and electrochemical effects is studied. The electromechanical responses are investigated by means of electrochemical impedance spectroscopy and bending displacement measurements. We develop a theoretical model that allows us to rationalize the electromechanical properties of the bucky-gel actuators. This model takes into account electrochemical stress due to the intercalation (de-intercalation) process, which generates the strain and bending of the actuators. We then analyze the relationship between the strain and the real part of the complex capacitance by introducing a strain–capacitance coefficient. This coefficient is related to the electrochemical stress and the amount of the ionic adsorption (desorption) at the double-layer. From a practical point of view, the determination of the strain–capacitance coefficient is helpful for characterizing and optimizing the performance of electrochemical actuators.

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