A transition metal complex, oxovanadium(IV) salen (where salen represents N,N′-bis(salicylidene)ethylenediamine) is immobilized on glassy carbon (GC) electrodes and utilized for electrocatalytic oxidation of cysteine. In presence of oxovanadium(IV) salen, increased oxidation current is observed due to the effective oxidation of cysteine by the electrogenerated oxovanadium(V) salen species. The oxidation current linearly varies with the concentration of cysteine from 0.1 to 1.0？mM. The modified electrode has good sensitivity and low limit of detection. These properties make the oxovanadium(IV) salen as an effective electrocatalyst for the determination of cysteine. 1. Introduction Transition metal complexes of N,N′-bis(salicylidene)ethylenediamine (salen) are used as effective catalysts for several reactions including some electrochemical reactions [1, 2]. A variety of catalytic reactions are reported by metal salen complexes. For example, oxovanadium(IV) salen (VO2+-S) complex exhibits effective and selective catalysis for the conversion of aromatic and aliphatic aldehydes to cyanohydrin [3, 4]. Similarly, a number of metal complexes of vanadium(IV) which possess VO2+ unit have been synthesized and studied for their catalytic properties [5]. The catalytic efficiency and other characteristics of oxovanadium(IV) compounds depend on the nature of ligand, coordination number, and stereochemistry [6]. VO2+-S is already used for the electrocatalytic oxidation and subsequent determination of pyridoxine [7], ascorbic acid [8], sulphide [9], cysteine [6], and other analytes [10–12]. Recently, accurate determination of cysteine has attracted many researchers due to its important role in structural and functional modification of proteins [6]. Oxidation of cysteine gives information about structural and functional modification of proteins and it could be used as a destined radiation protector and cancer indicator [13, 14]. Thus, quantitative determination of cysteine and elucidating the cysteine oxidation mechanism are important in the protein chemistry [15, 16]. Cysteine oxidation and subsequent determination at bare electrodes suffer because of electrode fouling, low sensitivity, and high oxidation overpotential [5, 6]. These problems can be solved partially by the utilization of modified electrodes which normally contain a suitable electrocatalyst immobilized on the electrode surface [17, 18]. Electrocatalysts can be immobilized on the electrode surface in various ways using polymers containing covalently attached electrocatalyst, electrocatalyst immobilized
References
[1]
P. Ad？o, J. C. Pessoa, R. T. Henriques et al., “Synthesis, characterization, and application of vanadium-salan complexes in oxygen transfer reactions,” Inorganic Chemistry, vol. 48, no. 8, pp. 3542–3561, 2009.
[2]
C. Baleiz？o, B. Gigante, H. Garcia, and A. Corma, “Vanadyl salen complexes covalently anchored to an imidazolium ion as catalysts for the cyanosilylation of aldehydes in ionic liquids,” Tetrahedron Letters, vol. 44, no. 36, pp. 6813–6816, 2003.
[3]
Y. N. Belokon, M. North, and T. Parsons, “Vanadium-catalyzed asymmetric cyanohydrin synthesis,” Organic Letters, vol. 2, no. 11, pp. 1617–1619, 2000.
[4]
J. R. Zamian and E. R. Dockal, “Tetradentate Schiff base oxovanadium(IV) complexes,” Transition Metal Chemistry, vol. 21, no. 4, pp. 370–376, 1996.
[5]
Y. Abe, K. Nakabayashi, N. Matsukawa et al., “Novel crystal structure and mesomorphism appeared in oxovanadium(IV) salen complexes with 4-substituted long alkoxy chains,” Inorganic Chemistry Communications, vol. 7, no. 4, pp. 580–583, 2004.
[6]
J. R. Zamian, E. R. Dockal, G. Castellano, and G. Oliva, “Synthesis and characterization of [N,N′-ethylenebis(3-ethoxysalicylideneaminato)] oxovanadium(IV),” Polyhedron, vol. 14, no. 17-18, pp. 2411–2418, 1995.
[7]
L. G. Shaidarova, L. N. Davletshina, and G. K. Budnikov, “Flow-injection determination of water-soluble vitamins B1, B2, and B6 from the electrocatalytic response of a graphite electrode modified with a ruthenium(III) hexacyanoruthenate(II) film,” Journal of Analytical Chemistry, vol. 61, no. 5, pp. 502–509, 2006.
[8]
L. Tian, L. Chen, L. Liu, N. Lu, W. Song, and H. Xu, “Electrochemical determination of ascorbic acid in fruits on a vanadium oxide polypropylene carbonate modified electrode,” Sensors and Actuators, B: Chemical, vol. 113, no. 1, pp. 150–155, 2006.
[9]
R. Ando, S. Mori, M. Hayashi, T. Yagyu, and M. Maeda, “Structural characterization of pentadentate salen-type Schiff-base complexes of oxovanadium(IV) and their use in sulfide oxidation,” Inorganica Chimica Acta, vol. 357, no. 4, pp. 1177–1184, 2004.
[10]
M. A. Kamyabi and F. Aghajanloo, “Electrocatalytic oxidation and determination of nitrite on carbon paste electrode modified with oxovanadium(IV)-4-methyl salophen,” Journal of Electroanalytical Chemistry, vol. 614, no. 1-2, pp. 157–165, 2008.
[11]
F. Jalali, L. Miri, and M. Roushani, “Electrocatalytic determination of anti-hyperthyroid drug, methimazole, using a modified carbon-paste electrode,” African Journal of Pharmacy and Pharmacology, vol. 7, no. 6, pp. 269–274, 2013.
[12]
H. Kanso, N. Inguimbert, L. Barthelmebs et al., “Oxovanadium-salen and -salan complexes as effective labels for electrochemical immunosensing: a case study for estradiol detection,” Chemical Communications, vol. 50, no. 14, pp. 1658–1661, 2014.
[13]
Y. D. Zhao, W. D. Zhang, H. Chen, and Q. M. Luo, “Electrocatalytic oxidation of cysteine at carbon nanotube powder microelectrode and its detection,” Sensors and Actuators, B: Chemical, vol. 92, no. 3, pp. 279–285, 2003.
[14]
T. J. Mafatle and T. Nyokong, “Electrocatalytic oxidation of cysteine by molybdenum(V) phthalocyanine complexes,” Journal of Electroanalytical Chemistry, vol. 408, no. 1-2, pp. 213–218, 1996.
[15]
S. Maree and T. Nyokong, “Electrocatalytic behavior of substituted cobalt phthalocyanines towards the oxidation of cysteine,” Journal of Electroanalytical Chemistry, vol. 492, no. 2, pp. 120–127, 2000.
[16]
J. Zagal, C. Fierro, and R. Rozas, “Electrocatalytic effects of adsorbed cobalt phthalocyanine tetrasulfonate in the anodic oxidation of cysteine,” Journal of Electroanalytical Chemistry, vol. 119, no. 2, pp. 403–408, 1981.
[17]
T. C. Richards and A. J. Bard, “Electrogenerated chemiluminescence. 57. Emission from sodium 9,10-diphenylanthracene-2-sulfonate, thianthrenecarboxylic acids, and chlorpromazine in aqueous media,” Analytical Chemistry, vol. 67, no. 18, pp. 3140–3147, 1995.
[18]
C. Wei, A. J. Bard, and M. V. Mirkin, “Scanning electrochemical microscopy. 31. Application of SECM to the study of charge transfer processes at the liquid/liquid interface,” The Journal of Physical Chemistry, vol. 99, no. 43, pp. 16033–16042, 1995.
[19]
P. K. Rastogi, V. Ganesan, and S. Krishnamoorthi, “A promising electrochemical sensing platform based on a silver nanoparticles decorated copolymer for sensitive nitrite determination,” Journal of Materials Chemistry A, vol. 2, no. 4, pp. 933–943, 2014.
[20]
P. K. Rastogi, V. Ganesan, and S. Krishnamoorthi, “Ion exchange voltammetry at permselective copolymer modified electrode and its application for the determination of catecholamines,” Journal of Electroanalytical Chemistry, vol. 676, pp. 13–19, 2012.
[21]
L. Gorton, “Chemically modified electrodes for the electrocatalytic oxidation of nicotinamide coenzymes,” Journal of the Chemical Society, Faraday Transactions I: Physical Chemistry in Condensed Phases, vol. 82, no. 4, pp. 1245–1258, 1986.
[22]
T. F. Connors, J. F. Rusling, and A. Owlia, “Determination of standard potentials and electron-transfer rates for halobiphenyls from electrocatalytic data,” Analytical Chemistry, vol. 57, no. 1, pp. 170–174, 1985.
[23]
I. Willner, N. Lapidot, A. Riklin, R. Kasher, E. Zahavy, and E. Katz, “Electron-transfer communication in glutathione reductase assemblies: electrocatalytic, photocatalytic, and catalytic systems for the reduction of oxidized glutathione,” Journal of the American Chemical Society, vol. 116, no. 4, pp. 1428–1441, 1994.
[24]
G. E. Cabaniss, A. A. Diamantis, W. R. Murphy Jr., R. W. Linton, and T. J. Meyer, “Electrocatalysis of proton-coupled electron-transfer reactions at glassy carbon electrodes,” Journal of the American Chemical Society, vol. 107, no. 7, pp. 1845–1853, 1985.
[25]
M. F. S. Teixeira, L. H. Marcolino-Júnior, O. Fatibello-Filho, E. R. Dockal, and M. F. Bergamini, “An electrochemical sensor for L-dopa based on oxovanadium-salen thin film electrode applied flow injection system,” Sensors and Actuators B, vol. 122, no. 2, pp. 549–555, 2007.
[26]
S. Mohebbi and M. Abdi, “Unsymmetrical mononuclear and insoluble polynuclear oxo-vanadium(IV) Schiff-base complexes,” Journal of Coordination Chemistry, vol. 61, no. 21, pp. 3410–3419, 2008.
[27]
U. P. Azad and V. Ganesan, “Efficient sensing of nitrite by Fe immobilized Nafion modified electrodes,” Chemical Communications, vol. 46, no. 33, pp. 6156–6158, 2010.
[28]
C. Karuppiah, S. Palanisamy, and S.-M. Chen, “An ultrahigh selective and sensitive enzyme-free hydrogen peroxide sensor based on palladium nanoparticles and nafion-modified electrode,” Electrocatalysis, vol. 5, no. 2, pp. 177–185, 2014.
[29]
M. Pawlak and E. Bakker, “Chemical modification of polymer ion-selective membrane electrode surfaces,” Electroanalysis, vol. 26, no. 6, pp. 1121–1131, 2014.
[30]
P. K. Rastogi, S. Krishnamoorthi, and V. Ganesan, “Synthesis, characterization, and ion exchange voltammetry study on 2-acrylamido-2-methylpropane sulphonic acid and -(hydroxymethyl) acrylamide-based copolymer,” Journal of Applied Polymer Science, vol. 123, no. 2, pp. 929–935, 2012.
[31]
S. Ku, S. Palanisamy, and S.-M. Chen, “Highly selective dopamine electrochemical sensor based on electrochemically pretreated graphite and nafion composite modified screen printed carbon electrode,” Journal of Colloid and Interface Science, vol. 411, pp. 182–186, 2013.
[32]
U. P. Azad and V. Ganesan, “Efficient electrocatalytic oxidation and selective determination of isoniazid by Fe(tmphen)32+-exchanged Nafion-modified electrode,” Journal of Solid State Electrochemistry, vol. 16, no. 9, pp. 2907–2911, 2012.
[33]
A. Chakraborty, S. Ahamed, S. Pal, and S. K. Saha, “Cyclic voltammetric investigations of thiazine dyes on modified electrodes,” ISRN Electrochemistry, vol. 2013, Article ID 959128, 7 pages, 2013.
[34]
C.-H. Zhou, Z.-F. Shen, L.-H. Liu, and S.-M. Liu, “Preparation and functionality of clay-containing films,” Journal of Materials Chemistry, vol. 21, no. 39, pp. 15132–15153, 2011.
[35]
A. Walcarius, V. Ganesan, O. Larlus, and V. Valtchev, “Low temperature synthesis of zeolite films on glassy carbon: towards designing molecularly selective electrochemical devices,” Electroanalysis, vol. 16, no. 18, pp. 1550–1554, 2004.
[36]
C. Mousty, “Sensors and biosensors based on clay-modified electrodes—new trends,” Applied Clay Science, vol. 27, no. 3-4, pp. 159–177, 2004.
[37]
V. Ganesan and R. Ramaraj, “In situ spectroelectrochemical studies of phenothiazine dyes at clay coated electrodes,” Journal of Electroanalytical Chemistry, vol. 490, no. 1-2, pp. 54–61, 2000.
[38]
L. Ding, Q. Xin, X. Dai, J. Zhang, and J. Qiao, “Evaluation of carbon-supported copper phthalocyanine (CuPc/C) as a cathode catalyst for fuel cells using Nafion as an electrolyte,” Ionics, vol. 19, no. 10, pp. 1415–1422, 2013.
[39]
V. Ganesan, S. A. John, and R. Ramaraj, “Multielectrochromic properties of methylene blue and phenosafranine dyes incorporated into Nafion film,” Journal of Electroanalytical Chemistry, vol. 502, no. 1-2, pp. 167–173, 2001.
[40]
A. Filer, H.-J. Choi, J.-M. Seo, and J.-B. Baek, “Two and three dimensional network polymers for electrocatalysis,” Physical Chemistry Chemical Physics, vol. 16, no. 23, pp. 11150–11161, 2014.
[41]
A. Walcarius, “Mesoporous materials and electrochemistry,” Chemical Society Reviews, vol. 42, no. 9, pp. 4098–4140, 2013.
[42]
M. Etienne, Y. Guillemin, D. Grosso, and A. Walcarius, “Electrochemical approaches for the fabrication and/or characterization of pure and hybrid templated mesoporous oxide thin films: a review,” Analytical and Bioanalytical Chemistry, vol. 405, no. 5, pp. 1497–1512, 2013.
[43]
I. F. Cheng, L. D. Whiteley, and C. R. Martin, “Ultramicroelectrode ensembles. Comparison of experimental and theoretical responses and evaluation of electroanalytical detection limits,” Analytical Chemistry, vol. 61, no. 7, pp. 762–766, 1989.
[44]
R. M. Penner and C. R. Martin, “Preparation and electrochemical characterization of ultramicroelectrode ensembles,” Analytical, vol. 59, no. 21, pp. 2625–2630, 1987.
[45]
V. P. Menon and C. R. Martin, “Fabrication and evaluation of nanoelectrode ensembles,” Analytical Chemistry, vol. 67, no. 13, pp. 1920–1927, 1995.
[46]
M. Pal, V. Ganesan, and U. P. Azad, “Photochemical oxygen reduction by zinc phthalocyanine and silver/gold nanoparticle incorporated silica thin films,” Thin Solid Films, vol. 525, pp. 172–176, 2012.
[47]
M. Pal and V. Ganesan, “Electrocatalytic activity of cobalt Schiff base complex immobilized silica materials towards oxygen reduction and hydrazine oxidation,” Catalysis Science and Technology, vol. 2, no. 11, pp. 2383–2388, 2012.
[48]
K. Yao, M. Taniguchi, M. Nakata, M. Takahashi, and A. Yamagishi, “Electrochemical scanning tunneling microscopy observation of ordered surface layers on an anionic clay-modified electrode,” Langmuir, vol. 14, no. 10, pp. 2890–2895, 1998.
[49]
J.-M. Zen, C.-W. Lo, and P.-J. Chen, “An enzymatic clay modified electrode for aerobic glucose monitoring with dopamine as mediator,” Analytical Chemistry, vol. 69, no. 8, pp. 1669–1673, 1997.
[50]
U. P. Azad, S. Turllapati, P. K. Rastogi, and V. Ganesan, “Tris (1,10-phenanthroline)iron(II)-bentonite film as efficient electrochemical sensing platform for nitrite determination,” Electrochimica Acta, vol. 127, pp. 193–199, 2014.
