The oxidation of cysteine by electrogenerated octacyanomolybdate (v)

Nekrassova, Olga; Kershaw, Jessica A.; Wadhawan, Jay D.; Lawrence, Nathan S.; Compton, Richard G.

doi:10.1039/b400141a

Cited by 14 publications

(10 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A variety of redox mediators have been investigated for the detection of amino acids via different electrochemical mechanistic pathways, for example, CE, [73][74][75] ECE, [76][77][78][79] and EC. 80,81 (In these mechanism abbreviations, E stands for an electron transfer step and C for a chemical reaction step.) Compton and co-workers investigated a wide series of redox mediators that react with the thiol moiety of cysteine; [75][76][77][78][79][80][81] for example, the chemical reaction between quinone, the redox mediator, and cysteine.…”

Section: Detection Of Amino Acids Via Redox Mediationmentioning

confidence: 99%

“…80,81 (In these mechanism abbreviations, E stands for an electron transfer step and C for a chemical reaction step.) Compton and co-workers investigated a wide series of redox mediators that react with the thiol moiety of cysteine; [75][76][77][78][79][80][81] for example, the chemical reaction between quinone, the redox mediator, and cysteine. [74][75][76]79 In the absence of cysteine, the redox voltammetry of quinone is observed.…”

Section: Detection Of Amino Acids Via Redox Mediationmentioning

confidence: 99%

“…Ferricyanide and octacyanomolybdate(V) were also investigated as possible redox mediators for cysteine detection. 80,81 In the same manner as for catecholmediated cysteine sensing, ferricyanide and octacyanomolybdate(V) are electrochemically formed and subsequently reduced to the initial species by the presence of cysteine in solution, the latter process forming the detection step. Finally, Miyaji et al synthesised a receptor with an amidopyridine and a ferrocene group.…”

Section: Detection Of Amino Acids Via Redox Mediationmentioning

confidence: 99%

See 2 more Smart Citations

Electrochemical strategies for the label-free detection of amino acids, peptides and proteins

Herzog

Arrigan

2007

Analyst

117

View full text Add to dashboard Cite

Electrochemical methods for the detection of amino acids, peptides, and proteins in a variety of media are reviewed. Label-free strategies in which the detection is based on the inherent electrochemical properties of the analyte are discussed. Various processes such as direct or mediated (in solution or immobilised) redox processes and interfacial ion transfers have been employed for the electrochemical detection and determination of the target analytes. The various methods covered encompass voltammetry at uncoated and modified electrodes and at immiscible liquid-liquid interfaces, potentiometry at polymer membrane electrodes and electrochemical impedance spectroscopy. The determination of the target analytes in complex biological matrices is discussed. The various approaches highlighted here illustrate the rich capabilities of electrochemical methods as simple, low-cost, sensitive tools for the determination of these important biological analytes at trace and ultra-trace levels.

show abstract

Section: Detection Of Amino Acids Via Redox Mediationmentioning

confidence: 99%

Section: Detection Of Amino Acids Via Redox Mediationmentioning

confidence: 99%

Section: Detection Of Amino Acids Via Redox Mediationmentioning

confidence: 99%

See 1 more Smart Citation

Electrochemical strategies for the label-free detection of amino acids, peptides and proteins

Herzog

Arrigan

2007

Analyst

117

View full text Add to dashboard Cite

show abstract

“…Although thiol levels in biological media are normally quite low [e.g. cysteine levels in blood and in urine are 4-240 × 10 −6 M and 20-80 × 10 −6 M, respectively, for healthy individuals (52)], they are within the detection range of the PQQ/SWNT/GC electrode. Figure 7.…”

Section: Applicationsmentioning

confidence: 99%

Electrochemical determination of thiols at single-wall carbon nanotubes and PQQ modified electrodes

Han¹

2005

Front Biosci

View full text Add to dashboard Cite

The electrocatalytic oxidation of thiols has been observed at a glassy carbon (GC) electrode coated with a single-wall carbon nanotube (SWNT) film. Fourteen thiols including L-cysteine (CySH) and glutathione were tested using the SWNT/GC electrode, and the cyclic voltammetry (CV) showed that each thiol was oxidized at much less positive potential than those at other electrodes such as bare GC and diamond electrodes. The SWNT/GC electrode was also modified with pyrroloquinoline quinone (PQQ) which showed a further improvement of the catalytic behavior of the SWNT/GC electrode: e.g. the oxidation peak current of CySH was observed at 0.27 V vs. Ag/AgCl in pH 7.5 phosphate buffer. The amperometic responses at these electrodes showed a linear relationship with the substrate concentration in a 10(-6)-10(-3) M range and 10(-6)-10(-7) M detection limits for several thiols including CySH, L-homocysteine, N-acetyl-L-cysteine, L-penicillamine and glutathione. These electrodes show a response time of 2-3 s and storage stabilities over 3 weeks. A PQQ/SWNT/GC electrode has been successfully applied for the assay of both L-cysteine and N-acetyl-L-cysteine in the dietary supplement.

show abstract

“…The use of bare electrode for electrochemical detection of lmethionine and l-cystine and thiols have a number of limitations, such as low sensitivity and reproducibility, high overpotential for oxidation, the slow electron transfer reaction and low stability over a wide range of solution compositions. Many transfer mediators such as quinones [4,5], lead ruthenate [6], cerium hexachloroplatinate [7], multivanadium substituted polyoxometalate [8], Prussian blue [9], copper hexacyanoferrate [10], phenothiazine derivatives [11], and octacyanomolybdate(V) [12] have been used for electrocatalytic oxidation of thiols. Compton and co-workers reviewed the electrochemical methods based on different modified electrodes for thiols detection [13].…”

Section: Introductionmentioning

confidence: 99%

Electrocatalytic Oxidation of Sulfur Containing Amino Acids at Renewable Ni‐Powder Doped Carbon Ceramic Electrode: Application to Amperometric Detection L‐Cystine, L‐Cysteine and L‐Methionine

Salimi

Roushani

2006

Electroanalysis

View full text Add to dashboard Cite

A sol-gel technique was used here to prepare a renewable carbon ceramic electrode modified with nickel powder. Cyclic voltammograms of the resulting modified electrode show stable and a well defined redox couple due to Ni(II)/ Ni(III) system with surface confined characteristics. The modified electrode shows excellent catalytic activity toward l-cystine, l-cysteine and l-methionine oxidation at reduced overpotential in alkaline solutions. In addition the antifouling properties at the modified electrode toward the above analytes and their oxidation products increases the reproducibility of results. l-cystine, l-cysteine and l-methionine were determined chronoamperometricaly at the surface of this modified electrode at pH range 9 -13. Under the optimized conditions the calibration curves are linear in the concentration range 1 -450 mM, 2 -90 mM and 0.2 -75 mM for l-cystine, l-methionine and l-cysteine determination, respectively. The detection limit and sensitivity were 0.64 mM, 3.8 nA/ mM for l-cystine, 2 mM, 5.6 nA/ mM for l-methionine and 0.2 mM and 8.1 nA/mM for l-cysteine. The advantageous of this modified electrode is high response, good stability and reproducibility, excellent catalytic activity for oxidation inert molecules at reduced overpotential and possibility of regeneration of the electrode surface by potential cycling for 5 minutes. Furthermore, the modified electrode has been prepared without using specific reagents. This sensor can be used as an amperometric detector for disulfides detection in chromatographic or flow systems.

show abstract

The oxidation of cysteine by electrogenerated octacyanomolybdate (v)

Cited by 14 publications

References 23 publications

Electrochemical strategies for the label-free detection of amino acids, peptides and proteins

Electrochemical strategies for the label-free detection of amino acids, peptides and proteins

Electrochemical determination of thiols at single-wall carbon nanotubes and PQQ modified electrodes

Electrocatalytic Oxidation of Sulfur Containing Amino Acids at Renewable Ni‐Powder Doped Carbon Ceramic Electrode: Application to Amperometric Detection L‐Cystine, L‐Cysteine and L‐Methionine

Contact Info

Product

Resources

About