A mechanistic study on the electrocatalysis of the Pu(iv)/Pu(iii) redox reaction at a platinum electrode modified with single-walled carbon nanotubes (SWCNTs) and polyaniline (PANI)

Gupta, Ruma; Guin, Saurav K.

doi:10.1039/c1ra01010g

Cited by 41 publications

(19 citation statements)

References 24 publications

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“…The peak current varied linearly with square root of scan rate (Table S5) for all the three compounds. Moreover, the slope of the plot of log

I

versus log

υ

was obtained as 0.471, 0.535, 0.395 respectively for XT, TP and CF closer to the theoretical value of 0.50 , indicating the diffusion controlled nature of the electrode processes.…”

Section: Resultsmentioning

confidence: 99%

Non‐enzymatic Electrochemical Sensor for the Simultaneous Determination of Xanthine, its Methyl Derivatives Theophylline and Caffeine as well as its Metabolite Uric Acid

Jesny

Kumar

2017

Electroanalysis

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Xanthine and its methyl derivatives, theophylline and caffeine are purines which find important roles in biological systems. The simultaneous voltammetric behaviour of these purines has been studied on a glassy carbon electrode modified with an electropolymerised film of para amino benzene sulfonic acid. Well defined and well separated peaks were obtained for the oxidation of xanthine, theophylline and caffeine on the polymer modified electrode in the square wave mode. The experimental requirements to obtain the best results for individual as well as simultaneous determination were optimised. The signal for the electro‐oxidation was found to be free of interferences from each other in the range 0.9 – 100 μM in the case of xanthine and from 10–100 μM in the case of theophylline and caffeine with detection limits 0.35 μM, 7.02 μM and 11.95 μM respectively. The simultaneous determination of uric acid, the final metabolic product of xanthine oxidation in biological systems could also be accomplished along with xanthine, theophylline and caffeine atphysiological pH. The mechanistic aspects of the electro‐oxidation on the polymer modified electrode was also studied using linear sweep voltammetry. Chronoamperometry was employed to determine the diffusion coefficient of these xanthines. The developed sensor has been successfully demonstrated to be suitable for the determination of these compounds in real samples without much pre‐treatment.

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“…The peak current varied linearly with square root of scan rate (Table S5) for all the three compounds. Moreover, the slope of the plot of log

I

versus log

υ

was obtained as 0.471, 0.535, 0.395 respectively for XT, TP and CF closer to the theoretical value of 0.50 , indicating the diffusion controlled nature of the electrode processes.…”

Section: Resultsmentioning

confidence: 99%

Non‐enzymatic Electrochemical Sensor for the Simultaneous Determination of Xanthine, its Methyl Derivatives Theophylline and Caffeine as well as its Metabolite Uric Acid

Jesny

Kumar

2017

Electroanalysis

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“…Therefore, all the experiments were performed with proper training and great care in a suitable place under safe conditions. 33 Guaranteed reagent (G.R.) grade sulphuric acid (H 2 SO 4 ), extra pure ACS grade uranyl nitrate hexahydrate [UO 2 (NO 3 ) 2 $6H 2 O] were used as received.…”

Section: Methodsmentioning

confidence: 99%

Electrochemistry of actinides on reduced graphene oxide: craving for the simultaneous voltammetric determination of uranium and plutonium in nuclear fuel

2015

Self Cite

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“…A mixture of both mechanisms is possible in real systems. To distinguish between both processes, log|i p | (where |i p | is an absolute peak current value), was plotted against log(v) (where v is the scan rate in mV/s) (Gupta et al, 2012 ). The results showed a small contribution from the adsorption-controlled pathway in the case of unsubstituted hydroquinone 1 on pyrite surfaces, with the slope of 0.56 ( R 2 = 0.994) for the cathodic peak and 0.58 ( R 2 = 0.985) for the anodic peak, however slopes for 2 are 0.43 ( R 2 = 0.999) and 0.45 ( R 2 = 0.996) for pyrite electrode and 0.35 ( R 2 = 0.987) and 0.42 ( R 2 = 0.992) for 3 on magnetite electrode, showed that both processes were fully diffusion-controlled.…”

Section: Resultsmentioning

confidence: 99%

Electron Transfer between Electrically Conductive Minerals and Quinones

Taran

2017

Front. Chem.

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Long-distance electron transfer in marine environments couples physically separated redox half-reactions, impacting biogeochemical cycles of iron, sulfur and carbon. Bacterial bio-electrochemical systems that facilitate electron transfer via conductive filaments or across man-made electrodes are well-known, but the impact of abiotic currents across naturally occurring conductive and semiconductive minerals is poorly understood. In this paper I use cyclic voltammetry to explore electron transfer between electrodes made of common iron minerals (magnetite, hematite, pyrite, pyrrhotite, mackinawite, and greigite), and hydroquinones—a class of organic molecules found in carbon-rich sediments. Of all tested minerals, only pyrite and magnetite showed an increase in electric current in the presence of organic molecules, with pyrite showing excellent electrocatalytic performance. Pyrite electrodes performed better than commercially available glassy carbon electrodes and showed higher peak currents, lower overpotential values and a smaller separation between oxidation and reduction peaks for each tested quinone. Hydroquinone oxidation on pyrite surfaces was reversible, diffusion controlled, and stable over a large number of potential cycles. Given the ubiquity of both pyrite and quinones, abiotic electron transfer between minerals and organic molecules is likely widespread in Nature and may contribute to several different phenomena, including anaerobic respiration of a wide variety of microorganisms in temporally anoxic zones or in the proximity of hydrothermal vent chimneys, as well as quinone cycling and the propagation of anoxic zones in organic rich waters. Finally, interactions between pyrite and quinones make use of electrochemical gradients that have been suggested as an important source of energy for the origins of life on Earth. Ubiquinones and iron sulfide clusters are common redox cofactors found in electron transport chains across all domains of life and interactions between quinones and pyrite might have been an early analog of these ubiquitous systems.

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A mechanistic study on the electrocatalysis of the Pu(iv)/Pu(iii) redox reaction at a platinum electrode modified with single-walled carbon nanotubes (SWCNTs) and polyaniline (PANI)

Cited by 41 publications

References 24 publications

Non‐enzymatic Electrochemical Sensor for the Simultaneous Determination of Xanthine, its Methyl Derivatives Theophylline and Caffeine as well as its Metabolite Uric Acid

Non‐enzymatic Electrochemical Sensor for the Simultaneous Determination of Xanthine, its Methyl Derivatives Theophylline and Caffeine as well as its Metabolite Uric Acid

Electrochemistry of actinides on reduced graphene oxide: craving for the simultaneous voltammetric determination of uranium and plutonium in nuclear fuel

Electron Transfer between Electrically Conductive Minerals and Quinones

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