Preparation of multiwall carbon nanotubes film modified electrode and its application to simultaneous determination of oxidizable amino acids in ion chromatography.

A multiwall carbon nanotubes (MWNTs) film modified electrode was prepared and used as an amperometric sensor for the simultaneous determination of oxidizable amino acids including cysteine, tryptophane and tyrosine. The electrochemical behaviors of these amino acids at this modified electrode were studied by cyclic voltammetry (CV). The results indicated that the MWNTs chemically modified electrode (CME) exhibited efficient electrocatalytic activity towards the oxidation of these amino acids with relatively high sensitivity, stability and long-life. Following separation by ion chromatography (IC) with 2.0 x 10(-3) mol l(-1) citric acid buffer solution (pH 6.5) as eluent, cysteine, tryptophane and tyrosine could be determined by the MWNTs CME successfully. Under the optimal conditions, the detection limits were 7.0 x 10(-7) mol l(-1) for cysteine, 2.0 x 10(-7) mol l(-1) for tryptophane and 3.5 x 10(-7) mol l(-1) for tyrosine at the signal-to-noise of 3, respectively. The method was applied successfully to the determination of these substances in plasma.

[1]  Richard P. Baldwin,et al.  Constant-potential amperometric detection of underivatized amino acids and peptides at a copper electrode , 1991 .

[2]  Ray H. Baughman,et al.  Electrochemical studies of single-wall carbon nanotubes in aqueous solutions , 2000 .

[3]  T. Cataldi,et al.  Copper dispersed into polyaniline films as an amperometric sensor in alkaline solutions of amino acids and polyhydric compounds , 1996 .

[4]  Charles M. Lieber,et al.  Covalently functionalized nanotubes as nanometre- sized probes in chemistry and biology , 1998, Nature.

[5]  Z. Gu,et al.  Investigation of the electrochemical and electrocatalytic behavior of single-wall carbon nanotube film on a glassy carbon electrode. , 2001, Analytical chemistry.

[6]  T. Cataldi,et al.  Amperometric determination of underivatized amino acids at a nickel-modified gold electrode by anion-exchange chromatography. , 2000, Journal of chromatography. A.

[7]  Zhennan Gu,et al.  Direct electrochemistry of cytochrome c at a glassy carbon electrode modified with single-wall carbon nanotubes. , 2002, Analytical chemistry.

[8]  Z. Gu,et al.  Electrocatalytic oxidation of 3,4-dihydroxyphenylacetic acid at a glassy carbon electrode modified with single-wall carbon nanotubes , 2001 .

[9]  H. Dai,et al.  Self-oriented regular arrays of carbon nanotubes and their field emission properties , 1999, Science.

[10]  P. Tauler,et al.  Participation of blood cells in the changes of blood amino acid concentrations during maximal exercise. , 2000, The Journal of nutritional biochemistry.

[11]  Richard J. Coles,et al.  Protein electrochemistry at carbon nanotube electrodes , 1997 .

[12]  P. Ajayan.  Nanotubes from Carbon. , 1999, Chemical reviews.

[13]  Bin Wang,et al.  Gas chromatography-mass spectrometry method for determination of phenylalanine and tyrosine in neonatal blood spots. , 2002, Journal of chromatography. B, Analytical technologies in the biomedical and life sciences.

[14]  T. Takeuchi,et al.  Nickel-titanium alloy electrodes for stable amperometric detection of underivatized amino acids in anion-exchange chromatography. , 2001, Talanta.

[15]  N. Avdalović,et al.  An Integrated Amperometry Waveform for the Direct, Sensitive Detection of Amino Acids and Amino Sugars Following Anion-Exchange Chromatography , 1999 .

[16]  W. Frankenberger,et al.  Pulsed Amperometric Detection of Amino Acids Separated by Anion Exchange Chromatography , 1992 .

[17]  M. Koller,et al.  Derivatization of peptides for their determination by chromatographic methods , 1997 .

[18]  R. Zare,et al.  Analysis of underivatized amino acids by capillary electrophoresis using constant potential amperometric detection , 1995, Electrophoresis.

[19]  Shirley Dex,et al.  JR 旅客販売総合システム（マルス）における運用及び管理について , 1991 .

[20]  C. O. Huber,et al.  A nickel oxide amperometric detector in the chromatographic separation of amino acids , 1985 .

[21]  G. G. Stokes.  "J." , 1890, The New Yale Book of Quotations.

[22]  L. Kartsova,et al.  Analysis of amino acids in human serum by isocratic reversed-phase high-performance liquid chromatography with electrochemical detection. , 2001, Journal of chromatography. A.

[23]  A. Rinzler,et al.  Carbon nanotube actuators , 1999, Science.

[24]  T. N. Todorov,et al.  Carbon nanotubes as long ballistic conductors , 1998, Nature.

[25]  M. S. Dresselhaus,et al.  Down the straight and narrow , 1992, Nature.

[26]  C. R. Martin,et al.  Carbon nanotubule membranes for electrochemical energy storage and production , 1998, Nature.