Analytical applications of a Carbon Nanotube Composite Modified with Copper Microparticles as Detector in Flow Systems

GUSTAVO RIVAS

ANALYTICA CHIMICA ACTA

Elsevier

Año: 2006 vol. 577 p. 183 - 189

0003-2670

Abstract In this work we report on the successful use of a composite prepared by dispersion of multi-wall carbon nanotubes (1?5
m length, 20?50 nm diameter) and copper microparticles within mineral oil as detector for amino acids quantification in flow injection analysis and capillary ectrophoresis. The resulting electrode displays a highly sensitive amperometric detection of amino acids, based on the copper dissolution facilitated by the strong activity of amino acids as ligands of Cu(II). The sensor makes possible the detection of amino acids, electroactive or not, at very low potentials (0.000 V) and physiological pH. A correlation between the sensitivity for the amino acids and the amount of copper within the composite is observed, demonstrating the importance of the metal in the sensor response. The best analytical performance is obtained for the electrode containing 12.0% (w/w) copper. The excellent results obtained with the carbon nanotube paste electrodes containing copper (CNTPE-Cu) as detector in flow systems makes them an interesting alternative for further analytical applications involving different bioanalytes.