Electrocatalytic activity of 4-nitrophthalonitrile-modified electrode for the l-glutathione detection

Lima, Phabyanno Rodrigues; Santos, Wilney J.R.; Oliveira, Adriano Bof de; Goulart, Marília Oliveira Fonseca; Kubota, Lauro T.

doi:10.1016/j.jpba.2008.03.006

Cited by 28 publications

(3 citation statements)

References 35 publications

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“…Therefore, the aim of this work is to construct a simple, stable, sensitive, and less expensive electrochemical sensor based on gold nanoparticles, nafion, and graphite for the determination of glutathione using CV and differential pulse voltammetry (DPV) techniques. There are several electrochemical methods mentioned in the literature with variable detection limits achieved [36,[41][42][43]. The main advantage of the new surface presented is the significant low detection limit achieved.…”

Section: Introductionmentioning

confidence: 99%

Novel sensor based on carbon paste/Nafion® modified with gold nanoparticles for the determination of glutathione

2012

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Several problems for the direct electrochemical oxidation of reduced glutathione (GSH) challenge the usage of electroanalytical techniques for its determination. In this work, the electrochemical oxidation of GSH catalyzed by gold nanoparticles electrodeposited on Nafion modified carbon paste electrode in 0.04 mol L(-1) universal buffer solution (pH 7.4) is proved successful. The effect of various experimental parameters including pH, scan rate and stability on the voltammetric response of GSH was investigated. At the optimum conditions, the concentration of GSH was determined using differential pulse voltammetry (DPV) in two concentration ranges: 0.1 × 10(-7) to 1.6 × 10(-5) mol L(-1) and 2.0 × 10(-5) to 2.0 × 10(-4) mol L(-1) with correlation coefficients 0.9988, 0.9949 and the limit of detections (LOD) are 3.9 × 10(-9) mol L(-1) and 8.2 × 10(-8) mol L(-1), respectively, which confirmed the sensitivity of the electrode. The high sensitivity, wide linear range, good stability and reproducibility, and the minimal surface fouling make this modified electrode useful for the determination of spiked GSH in urine samples and in tablet with excellent recovery results obtained.

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Section: Introductionmentioning

confidence: 99%

Novel sensor based on carbon paste/Nafion® modified with gold nanoparticles for the determination of glutathione

2012

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“…For this reason, the 3,5-dinitrobenzoic acid (3,5- strategically selected to compose the interface as catalyst in face of its chemical structure to be highly versatile, for instance, (i) presence of the carboxylic group, making possible, to be covalently linked with the amine groups as recently reported [24] and (ii) the nitro groups, in their oxidized state, have no electrocatalytic activity for thiols or NADH oxidation as recently reported [25][26][27][28][29]. However, when electrochemically reduced in situ, the nitro group is transformed into a hydroxylamine functionality.…”

Section: Introductionmentioning

confidence: 99%

In situ activated 3,5-dinitrobenzoic acid covalent attached to nanostructured platform for NADH electrooxidation

Santhiago

Lima

Santos

et al. 2009

Electrochimica Acta

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“…Their synthesis comes from the most abundant thiol – reduced glutathione. To detect these compounds many various methods and techniques have been employed [23,24,26–30], including sensors and biosensors [31–33]. However, uptake and transport as well as storage of heavy metals through plant tissues remain still unclear.…”

Section: Introductionmentioning

confidence: 99%

Sunflower Plants as Bioindicators of Environmental Pollution with Lead (II) Ions

Kryštofová

Shestivská

Galiová

et al. 2009

Sensors

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In this study, the influence of lead (II) ions on sunflower growth and biochemistry was investigated from various points of view. Sunflower plants were treated with 0, 10, 50, 100 and/or 500 μM Pb-EDTA for eight days. We observed alterations in growth in all experimental groups compared with non-treated control plants. Further we determined total content of proteins by a Bradford protein assay. By the eighth day of the experiment, total protein contents in all treated plants were much lower compared to control. Particularly noticeable was the loss of approx. 8 μg/mL or 15 μg/mL in shoots or roots of plants treated with 100 mM Pb-EDTA. We also focused our attention on the activity of alanine transaminase (ALT), aspartate transaminase (AST) and urease. Activity of the enzymes increased with increasing length of the treatment and applied concentration of lead (II) ions. This increase corresponds well with a higher metabolic activity of treated plants. Contents of cysteine, reduced glutathione (GSH), oxidized glutathione (GSSG) and phytochelatin 2 (PC2) were determined by high performance liquid chromatography with electrochemical detection. Cysteine content declined in roots of plants with the increasing time of treatment of plants with Pb-EDTA and the concentration of toxic substance. Moreover, we observed ten times higher content of cysteine in roots in comparison with shoots. The observed reduction of cysteine content probably relates with its utilization for biosynthesis of GSH and phytochelatins, because the content of GSH and PC2 was similar in roots and shoots and increased with increased treatment time and concentration of Pb-EDTA. Moreover, we observed oxidative stress caused by Pb-EDTA in roots where the GSSG/GSH ratio was about 0.66. In shoots, the oxidative stress was less distinctive, with a GSSG/GSH ratio 0.14. We also estimated the rate of phytochelatin biosynthesis from the slope of linear equations plotted with data measured in the particular experimental group. The highest rate was detected in roots treated with 100 μM of Pb-EDTA. To determine heavy metal ions many analytical instruments can be used, however, most of them are only able to quantify total content of the metals. This problem can be overcome using laser induced breakdown spectroscopy, because it is able to provide a high spatial-distribution of metal ions in different types of materials, including plant tissues. Data obtained were used to assemble 3D maps of Pb and Mg distribution. Distribution of these elements is concentrated around main vascular bundle of leaf, which means around midrib.

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Electrocatalytic activity of 4-nitrophthalonitrile-modified electrode for the l-glutathione detection

Cited by 28 publications

References 35 publications

Novel sensor based on carbon paste/Nafion® modified with gold nanoparticles for the determination of glutathione

Novel sensor based on carbon paste/Nafion® modified with gold nanoparticles for the determination of glutathione

In situ activated 3,5-dinitrobenzoic acid covalent attached to nanostructured platform for NADH electrooxidation

Sunflower Plants as Bioindicators of Environmental Pollution with Lead (II) Ions

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