A sensor based on glassy carbon (GC) electrode modified with bis(1,10-phenantroline)copper(II) bis(tetracyanoquinodimethanide) [Cu(phen)2(TCNQ)2] immobilized in a poly-l-lysine (PLL) film is proposed for catechol (CA) determination with differential pulse voltammetry (DPV) technique. The modified electrode showed excellent stability as well as the ability to detect catechol in nanomolar catechol levels. A linear response range from 10 nmol l-1 up to 20 μmol l-1 with a sensitivity of 2.29 μA l μmol-1 cm-2 and detection limit of 3.0 nmol l-1 were observed in the optimized conditions. The repeatability of the mesurements with the proposed sensor was 2% evaluated in term of relative standard deviation, with n = 10 for 10 μmol l-1 CA. Cyclic voltammetry and rotating disk electrode (RDE) experiments indicated that the catechol oxidation reaction involves two-electrons and a heterogenous rate constant (k) average value of about 1.30 × 103 M-1 s-1. The catechol diffusion coefficient (Do) value was estimated as being 7.6 × 10-6 cm2 s-1. The sensor was successfully applied for CA determination in powdered guarana samples. © 2005 Elsevier B.V. All rights reserved.1171274281Solná, R., Sapelnikova, S., Skládal, P., Winther-Nielsen, M., Carlsson, C., Emnéus, J., Ruzgas, T., Multienzyme electrochemical array sensor for determination of phenols and pesticides (2005) Talanta, 65, pp. 349-357Lin, X., Gong, J., Electrocatalytic oxidation and selective detection of dopamine at a 5,5-ditetradecyl-2-(2-trimethyl-ammonioethyl)-1,3-dioxane bromide self-assembled bilayer membrane modified glassy carbon electrode (2004) Anal. Chim. Acta, 507, pp. 259-265Yoshitake, T., Kehr, J., Yoshitake, S., Fujino, K., Nohta, H., Yamaguchi, M., Determination of serotonin, noradrenaline, dopamine and their metabolites in rat brain extracts and microdialysis samples by column liquid chromatography with fluorescence detection following derivatization with benzylamine and 1,2-diphenylethylenediamine (2004) J. Chromatogr. B, 807, pp. 177-183Powley, M.W., Carloson, G.P., Species comparison of hepatic and pulmonary metabolism of benzene (1999) Toxicology, 139, pp. 207-217Talcott, S.T., Passeretti, S., Duncan, C.E., Gorbet, D.W., Polyphenolic content and sensory properties of normal and high oleic acid peanuts (2005) Food Chem., 90, pp. 379-388Cui, H., He, C., Zhao, G., Determination of polyphenols by high-performance liquid chromatography with inhibited chemiluminescence detection (1999) J. Chromatogr. A, 855, pp. 171-179Maurer, H.H., Bickeboeller-Friedrich, J., Kraemer, T., Gas chromatographic-mass spectrometric procedures for determination of the catechol-O-methyltransferase (COMT) activity and for detection of unstable catecholic metabolites in human and rat liver preparations after (COMT) catalyzed in statu nascendi derivatization using S-adenosylmethionine (2000) J. Chromatogr. B, 739, pp. 325-335Fiehn, O., Jekel, M., Analysis of phenolic compounds in industrial wastewater with high-performance liquid chromatography and post-column reaction detection (1997) J. Chromatogr. A, 769, pp. 189-200Sotomayor, M.D.P.T., Tanaka, A.A., Kubota, L.T., Tris (2,2′-bipyridil) copper (II) chloride complex: a biomimetic tyrosinase catalyst in the amperometric sensor construction (2003) Electrochim. Acta, 48, pp. 855-865Carvalho, R.M., Mello, C., Kubota, L.T., Simultaneous determination of phenol isomers in binary mixtures by differential pulse voltammetry using carbon fibre electrode and neural network with pruning as a multivariate calibration tool (2000) Anal. Chim. Acta, 420, pp. 109-121Mello, L.D., Stomayor, M.D.P.T., Kubota, L.T., HRP-based amperometric biosensor for the polyphenols determination in vegetables extract (2003) Sens. Actuators B: Chem., 96, pp. 636-645Murray, R.W., (1984) Electroanalytical Chemistry, , Bard A.J. (Ed), Marcel Dekker, New YorkRedepenning, J.G., Chemically modified electrodes-a general overview (1987) Tracs-Trends Anal. Chem., 6, pp. 18-22Razmi, H., Agazadeh, M., Habibi-A, B., Electrocatalytic oxidation of dopamine at aluminum electrode modified with nickel pentacyanonitrosylferrate films, synthesized by electroless procedure (2003) J. Electroanal. Chem., 547, pp. 25-33Damos, F.S., Sotomayor, M.D.T., Kubota, L.T., Tanaka, S.M.C.N., Tanaka, A.A., Iron(III) tetra-(N-methyl-4-pyridyl)-porphyrin as a biomimetic catalyst of horseradish peroxidase on the electrode surface: an amperometric sensor for phenolic compound determinations (2003) Analyst, 128, pp. 225-259Dempsey, E., Diamond, D., Collier, A., Development of a biosensor for endocrine disrupting compounds based on tyrosinase entrapped within a poly(thionine) film (2004) Biosens. Bioelectron., 20, pp. 367-377Rajesh, W., Kaneto, K., Amperometric tyrosinase based biosensor using an electropolymerized PTS-doped polypyrrole film as an entrapment support (2004) React. Funct. Polym., 59, pp. 163-169Campuzano, S., Serra, B., Pedrero, M., Villena, F.J.M., Pingarrón, J.M., Amperometric flow-injection determination of phenolic compounds at self-assembled monolayer-based tyrosinase biosensors (2003) Anal. Chim. Acta, 494, pp. 187-197Cosnier, S., Szunerits, S., Markks, R.S., Lellouche, J.P., Perie, K., Mediated electrochemical detection of catechol by tyrosinase-based poly(dicarbazole) electrodes (2001) J. Biochem. Biophys. Methods, 50, pp. 65-77Dantoni, P., Serrano, S.H.P., Brett, A.M.O., Gutz, J.G.R., Flow-injection determination of catechol with a new tyrosinase/DNA biosensor (1998) Anal. Chim. Acta, 366, pp. 137-145Haghighi, B., Gordon, L., Ruzgas, T., Josson, L.J., Characterization of graphite electrodes modified with laccase from Trametes versicolor and their use for bioelectrochemical monitoring of phenolic compounds in flow injection analysis (2003) Anal. Chim. Acta, 487, pp. 3-14Izacumen, N., Bouchta, D., Zejli, H., Kaoutit, M.E., Stalcup, A.M., Temsamani, K.R., Electrosynthesis and analytical performances of functionalized poly (pyrrole/β-cyclodextrin) films (2005) Talanta, 66, pp. 111-117Sotomayor, M.D.P.T., Tanaka, A.A., Kubota, L.T., Development of an enzymeless biosensor for the determination of phenolic compounds (2002) Anal. Chim. Acta, 455, pp. 215-223Luz, R.C.S., Damos, F.S., Oliveira, A.B., Beck, J., Kubota, L.T., Voltammetric determination of 4-nitrophenol at a lithium tetracyanoethylenide (LiTCNE) modified glassy carbon electrode (2004) Talanta, 64, pp. 935-942Luz, R.C.S., Damos, F.S., Oliveira, A.B., Beck, J., Kubota, L.T., Development of a sensor based on tetracyanoethylenide (LiTCNE)/poly-l-lysine (PLL) for dopamine determination (2005) Electrochim. Acta, 50, pp. 2675-2683Khoo, S.B., John, K.F., Stanley Pons, Electrolyte effects on the cyclic voltammetry of TCNQ and TCNE (1986) J. Electroanal. Chem., 215, pp. 273-285Zhao, S., Lennox, R., Bioelectrocatalysis at organic conducting salt electrodes. Use of hexamethylenetetratellurafulvalene tetracyanoquinodimethane (HMTTeF-TCNQ) as a versatile electrode material (1993) J. Electroanal. Chem., 346, pp. 161-173Melby, L.R., Harder, R.J., Hertler, W.R., Mahler, W., Benson, R.E., Mochel, W.E., Substituted quinodimethans. 2. Anion-radical derivatives and complexes of 7,7,8,8-tetracyanoquinodimethane (1962) J. Am. Chem. Soc., 84, pp. 3374-3387Schwartz, M., Hatfield, W.E., Spectroscopic and magnetic studies of 2 electrically conducting charge-transfer compounds of 7,7,8,8-tetracyanoquinodimethanide with cationic copper-chelates (1987) Inorg. Chem., 26, pp. 2823-2825Zhu, Z., Na-Qiang, L., 9,10-Anthraquinone modified glassy carbon electrode and its application for hemoglobin determination (1998) Electroanalysis, 10, pp. 643-646Magna, A., Salomão, A.A., Vila, M.M.D.C., Tubino, M., Comparative study of two spectrophotometric reagents for catechol analysis in guaraná seeds powder (2003) J. Braz. Chem. Soc., 14, p. 129Pandey, P.C., Upadhyay, S., Pathak, H.C., Pandey, C.M.D., Sensitivity, selectivity and reproducibility of some mediated electrochemical biosensors/sensors (1998) Anal. Lett., 31, pp. 2327-2348Andrieux, C.P., Savéant, J.M., Heterogeneous (chemically modified electrodes, polymer electrodes) vs. homogeneous catalysis of electrochemical reactions (1978) J. Electroanal. Chem., 93, pp. 163-168Bard, A.J., Faulkner, L.R., (1980) Electrochemical Methods, Fundamentals and Applications, , Wiley, New YorkDurgbanshi, A., Kok, W.T., Capillary electrophoresis and electrochemical detection with a conventional detector cell (1998) J. Chromatogr. A, 798, pp. 289-296Razmi, H., Agazadeh, M., Habibi-A, B., Electrocatalytic oxidation of dopamine at aluminum electrode modified with nickel pentacyanonitrosylferrate films, synthetized by electroless procedure (2003) J. Electroanal. Chem., 547, pp. 25-33Razmi, H., Azadbakkht, A., Electrochemical characteristic of dopamine oxidation at palladium hexacyanoferrate film, electroless plated on aluminum electrode (2005) Electrochim. Acta, 50, pp. 2193-2201Laviron, E., Electrochemical reactions with protonations at equilibrium: part II. The 1e, 1 H+ reaction (four-member square scheme) for a heterogeneous reaction (1981) J. Electroanal. Chem., 124, pp. 1-7Richard, J.A., Whitson, P.E., Evans, D.H., Electrochemical oxidation of 2,4,6-tri-tert-butylphenol (1975) J. Electroanal. Chem., 63, pp. 311-327Papouchado, L., Sandford, R.W., Petrie, G., Adams, R.N., Anodic oxidation pathways of phenolic compounds part 2. Stepwise electron transfers and coupled hydroxylations (1975) J. Electroanal. Chem., 65, pp. 275-284Kim, M.A., Lee, W.Y., Amperometric phenol biosensor based on sol-gel silicate/Nafion composite film (2003) Anal. Chim. Acta, 479, pp. 143-150Analytical Methods Commitee, Recommendations for the definition, estimationand use of the detection limit (1987) Analyst, 112, pp. 199-204Henman, A.R., Guarana (paullinia-cupana var sorbilis)-ecological and social perspectives on an economic plant of the central amazon basin (1982) J. Pharm. Pharmacol., 6, pp. 311-338