Voltammetric behavior of multi-walled carbon nanotubes modified electrode-hexacyanoferrate(II) electrocatalyst system as a sensor for determination of captopril

Rezaei, Behzad; Damiri, Sajjad

doi:10.1016/j.snb.2008.05.004

Cited by 200 publications

(74 citation statements)

References 70 publications

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“…Thus, the composite material prepared with a higher concentration of Au and Ag (Gr-AuAg-1.5) greatly facilitated the direct transfer of electrons between captopril and the electrode surface. This is in contrast with many previously published papers, which have generally reported the employment of a redox mediator either in solution 11 or adsorbed on the electrode surface 14 in order to enhance the oxidation of captopril molecules.…”

Section: Intensity (Au) 2θ (Degrees)contrasting

confidence: 84%

Direct electrochemical oxidation of S-captopril using gold electrodes modified with graphene-AuAg nanocomposites

Pogăcean

Biriş

Coroș

et al. 2014

IJN

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In this paper, we present a novel approach for the electrochemical detection of S -captopril based on graphene AuAg nanostructures used to modify an Au electrode. Multi-layer graphene (Gr) sheets decorated with embedded bimetallic AuAg nanoparticles were successfully synthesized catalytically with methane as the carbon source. The two catalytic systems contained 1.0 wt% Ag and 1.0 wt% Au, while the second had a larger concentration of metals (1.5 wt% Ag and 1.5 wt% Au) and was used for the synthesis of the Gr-AuAg-1 and Gr-AuAg-1.5 multicomponent samples. High-resolution transmission electron microscopy analysis indicated the presence of graphene flakes that had regular shapes (square or rectangular) and dimensions in the tens to hundreds of nanometers. We found that the size of the embedded AuAg nanoparticles varied between 5 and 100 nm, with the majority being smaller than 20 nm. Advanced scanning transmission electron microscopy studies indicated a bimetallic characteristic of the metallic clusters. The resulting Gr-AuAg-1 and Gr-AuAg-1.5 samples were used to modify the surface of commonly used Au substrates and subsequently employed for the direct electrochemical oxidation of S -captopril. By comparing the differential pulse voltammograms recorded with the two modified electrodes at various concentrations of captopril, the peak current was determined to be well-defined, even at relatively low concentration (10 −5 M), for the Au/Gr-AuAg-1.5 electrode. In contrast, the signals recorded with the Au/Gr-AuAg-1 electrode were poorly defined within a 5×10 −6 to 5×10 −3 M concentration range, and many of them overlapped with the background. Such composite materials could find significant applications in nanotechnology, sensing, or nanomedicine.

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Section: Intensity (Au) 2θ (Degrees)contrasting

confidence: 84%

Direct electrochemical oxidation of S-captopril using gold electrodes modified with graphene-AuAg nanocomposites

Pogăcean

Biriş

Coroș

et al. 2014

IJN

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“…The area of the electrode was calculated using 1.0 mM K 3 Fe(CN) 6 as a probe at different scan rates. For a reversible process, the Randles-Sevcik formula has been used [14]. …”

Section: Instrumentationmentioning

confidence: 99%

Electrochemical Behavior of Chalcone at a Glassy Carbon Electrode and Its Analytical Applications

Naik¹,

Nandibewoor²

2012

AJAC

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A simple and rapid method was developed using cyclic, differential pulse and square wave voltammetric techniques for the determination of trace-level chalcone at a glassy carbon electrode. Chalcone could produce two anodic peaks at about 0.514 V and 1.478 V and a cathodic peak at about −0.689 V. The differential pulse voltammerty presents a good linear response as compared to square wave voltammetry in the range of 0.2 -10 μM with a detection limit of 0.18 μM. The proposed method was used successfully for its quantitative determination in spiked human plasma and urine as real samples.

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“…13 The purified MWCNTs were dispersed in acetonitrile (1.0 mg MWCNTs per 1.0 mL) using ultrasonic agitation to obtain a black suspension. The GCE was carefully polished with 0.05 μm alumina slurry on a polishing cloth, and was then washed in an ultrasonic bath of methanol and water, respectively.…”

Section: Preparation Of Mwcnt Suspension and Modified Gcementioning

confidence: 99%

Simultaneous Voltammetric Determination of Enrofloxacin and Ciprofloxacin in Urine and Plasma Using Multiwall Carbon Nanotubes Modified Glassy Carbon Electrode by Least-Squares Support Vector Machines

et al. 2010

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803Fluoroquinolones are a class of synthetic antibacterial agents, which are known for their broad spectrum of antibacterial activity. These compounds are derived from nalidixic acid and naphthyridine derivatives, which have been introduced for clinical applications in the livestock and farming industries.1 In this work, two important fluoroquinolones, namely enrofloxacin (1-cyclopropyl-7-(4-ethyl-1-piperazinyl)-6-fluoro-1,4-dihydro-4-oxo-3-quinolonecarboxylic acid) and ciprofloxacin (1-cyclopropyl-7-(1-piperazinyl)-6-fluoro-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid), were investigated and quantitatively analyzed by voltammetric methods. In several animal species, including pigs, enrofloxacin (ENRO) is de-ethylated to its primary metabolite, ciprofloxacin (CIPRO), 2 and both ENRO and CIPRO are found in the bile and urine of animals receiving ENRO. Electrochemical methods, such as polarography and voltammetry, have high sensitivity and are widely used in many areas of analytical chemistry.Recently, cathodic adsorptive stripping voltammetry on a static mercury drop electrode and principal-component regression have been applied for the determination of ENRO in the presence of CIPRO 10 at trace levels. However, the linear dynamic range of the method is too narrow, and the toxicity of mercury (as an electrode) has caused its application in routine laboratories to decline. At more negative potentials, many biological compounds are adsorbed on the surface of the Hg-electrode, diminishing the selectivity of the method. 10 On the other hand, simultaneous voltammetric determinations of ENRO and CIPRO have not been reported, since ENRO affects the oxidation potential of CIPRO and vice versa. Therefore, the direct determination of CIPRO in the presence of ENRO is not possible by univariate calibration methods.In this work, linear sweep voltammetry (LSV) used for the first time with a multiwall carbon nanotubes/glassy carbon electrode (MWCNT/GCE) provides a sensitive method for the determination of ENRO or CIPRO in the presence of the other without any pretreatment or separation. When MWCNT/GCE is used as a working electrode in the voltammetric method, ENRO affects the oxidation potential of CIPRO, whereas CIPRO does not affect that of ENRO. Because it was possible to measure ENRO without any interfering effect of CIPRO, a least-squares support vector machine (LS-SVM) model was constructed in this study to relate a CIPRO voltammogram to its concentration. The model predicts CIPRO concentration in both spiked human plasma and pharmaceutical samples. The proposed methodology is fast and simple, while it does not generate hazardous chemical wastes. Theory of Least Square Support Vector RegressionSupport vector machines (SVMs) based on statistical learning theory were introduced by Cortes and Vapnik.11 LS-SVMs are an alternate formulation of SVM described by Suykens et al. 12 Here, we only briefly describe the theory of LS-SVM. Linear least-squares models fit a linear relation between the spectrum xi and the reference va...

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Voltammetric behavior of multi-walled carbon nanotubes modified electrode-hexacyanoferrate(II) electrocatalyst system as a sensor for determination of captopril

Cited by 200 publications

References 70 publications

Direct electrochemical oxidation of S-captopril using gold electrodes modified with graphene-AuAg nanocomposites

Direct electrochemical oxidation of S-captopril using gold electrodes modified with graphene-AuAg nanocomposites

Electrochemical Behavior of Chalcone at a Glassy Carbon Electrode and Its Analytical Applications

Simultaneous Voltammetric Determination of Enrofloxacin and Ciprofloxacin in Urine and Plasma Using Multiwall Carbon Nanotubes Modified Glassy Carbon Electrode by Least-Squares Support Vector Machines

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