Simultaneous Voltammetric Determination of Paracetamol, Codeine and Caffeine on Diamond-like Carbon Porous Electrodes.

A porous electrode material combining the features of vertically aligned multi-walled carbon nanotubes (VAMWCNT) and diamond-like carbon films (DLC) have been developed for a highly sensitive electrochemical sensor. For working electrode preparation, DLC has been grown onto VAMWCNT, forming a porous, conductive and stable composite. The electrochemical performance of this DLC:VAMWCNT electrode has been investigated toward detection and analysis of three well-known molecules, namely paracetamol, codeine and caffeine. A ternary mixture of these analytes was simultaneously determined under optimum experimental conditions using square-wave voltammetry. Wide linear concentration ranges and the limits of detection of 3.34×10−7 mol L−1, 1.57×10−7 mol L−1 and 3.67×10−7 mol L−1 were obtained for paracetamol, codeine and caffeine, respectively. We conclude that the proposed voltammetric method and the DLC:VAMWCNT electrode comprise a reliable methodology for simultaneous determination of paracetamol, codeine and caffeine in biological matrix samples. [ABSTRACT FROM AUTHOR]