Carbon nanotube disposable detectors in microchip capillary electrophoresis for water‐soluble vitamin determination: Analytical possibilities in pharmaceutical quality control

In this work, the synergy of one mature example from “lab‐on‐chip” domain, such as CE microchips with emerging miniaturized carbon nanotube detectors in analytical science, is presented. Two different carbon electrodes (glassy carbon electrode (GCE) 3 mm diameter, and screen‐printed electrode (SPE) 0.3 mm×2.5 mm) were modified with multiwalled carbon nanotubes (MWCNTs) and their electrochemical behavior was evaluated as detectors in CE microchip using water‐soluble vitamins (pyridoxine, ascorbic acid, and folic acid) in pharmaceutical preparations as representative examples. The SPE modified with MWCNT was the best electrode for the vitamin analysis in terms of analytical performance. In addition, accurate determination of the three vitamins in four different pharmaceuticals was obtained (systematic error less than 9%) in only 400 s using a protocol that combined the sample analysis and the methodological calibration.

[1]  Roland Zengerle,et al.  Microfluidic platforms for lab-on-a-chip applications. , 2007, Lab on a chip.

[2]  Andreas Manz,et al.  Scaling and the design of miniaturized chemical-analysis systems , 2006, Nature.

[3]  A. Oberlin,et al.  Filamentous growth of carbon through benzene decomposition , 1976 .

[4]  M. S. de Vries,et al.  Cobalt-catalysed growth of carbon nanotubes with single-atomic-layer walls , 1993, Nature.

[5]  Heli Jantunen,et al.  Inkjet printing of electrically conductive patterns of carbon nanotubes. , 2006, Small.

[6]  Joseph Wang.  Nanomaterial-based electrochemical biosensors. , 2005, The Analyst.

[7]  S. Iijima.  Helical microtubules of graphitic carbon , 1991, Nature.

[8]  Marek Trojanowicz,et al.  Analytical applications of carbon nanotubes : a review , 2006 .

[9]  Gang Chen.  Carbon nanotube and diamond as electrochemical detectors in microchip and conventional capillary electrophoresis. , 2007, Talanta.

[10]  J Justin Gooding,et al.  Demonstration of the importance of oxygenated species at the ends of carbon nanotubes for their favourable electrochemical properties. , 2005, Chemical communications.

[11]  G. Whitesides.  The origins and the future of microfluidics , 2006, Nature.

[12]  Martin Pumera,et al.  Microchip electrophoresis with wall‐jet electrochemical detector: Influence of detection potential upon resolution of solutes , 2006, Electrophoresis.

[13]  S. Hernández,et al.  Enhanced application of square wave voltammetry with glassy carbon electrode coupled to multivariate calibration tools for the determination of B(6) and B(12) vitamins in pharmaceutical preparations. , 2003, Talanta.

[14]  T. Meyer,et al.  Electrocatalysis of proton-coupled electron-transfer reactions at glassy carbon electrodes , 1985 .

[15]  A. Manz,et al.  Micro total analysis systems. Latest advancements and trends. , 2006, Analytical chemistry.

[16]  M. Pumera,et al.  New materials for electrochemical sensing VI: Carbon nanotubes , 2005 .

[17]  Martin Pumera,et al.  Food analysis on microfluidic devices using ultrasensitive carbon nanotubes detectors. , 2007, Analytical chemistry.

[18]  T. Ichihashi,et al.  Single-shell carbon nanotubes of 1-nm diameter , 1993, Nature.

[19]  Alberto Escarpa,et al.  A fast and reliable route integrating calibration and analysis protocols for water‐soluble vitamin determination on microchip‐electrochemistry platforms , 2006, Electrophoresis.

[20]  Joseph Wang,et al.  Electrochemical Detection for Capillary Electrophoresis Microchips: A Review , 2005 .

[21]  M. Schwarz,et al.  Recent developments in detection methods for microfabricated analytical devices. , 2001, Lab on a chip.

[22]  C. Banks,et al.  New electrodes for old: from carbon nanotubes to edge plane pyrolytic graphite. , 2006, The Analyst.

[23]  T. Mukherjee,et al.  Free radical scavenging behavior of folic acid: evidence for possible antioxidant activity. , 2001, Free radical biology & medicine.

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

[25]  Martin Pumera,et al.  New materials for electrochemical sensing VII. Microfluidic chip platforms , 2006 .

[26]  M. Pumera,et al.  Spontaneous coating of carbon nanotubes with an ultrathin polypyrrole layer. , 2007, Chemistry.

[27]  Alberto Escarpa,et al.  CE microchips: An opened gate to food analysis , 2007, Electrophoresis.

[28]  Martin Pumera,et al.  Carbon nanotube detectors for microchip CE: Comparative study of single‐wall and multiwall carbon nanotube, and graphite powder films on glassy carbon, gold, and platinum electrode surfaces , 2007, Electrophoresis.

[29]  Martin Pumera,et al.  Carbon nanotubes contain residual metal catalyst nanoparticles even after washing with nitric acid at elevated temperature because these metal nanoparticles are sheathed by several graphene sheets. , 2007, Langmuir : the ACS journal of surfaces and colloids.