Development of voltammetric sensor based on polyimide-MWCNT composite membrane for rapid and highly sensitive detection of paracetamol

In this work, for low level detection of paracetamol (PA) a voltammetric sensor was obtained. Polyimidemultiwall carbon nanotube (PI-MWCNT) composite film was used for modification of platinum (Pt) electrode as selective membrane. Firstly, this PI-MWCNT film was synthesized with 2,5-diaminopyridine (DAP), 4,4'-oxydiphthalic anhydride (ODPA) and MWCNT as a reinforcement by thermal imidization technique. The morphology, micro and chemical structures of the obtained composite film were studied by Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and thermal analysis techniques. Then, the paracetamol sensor was prepared via the modification of Pt electrode with prepared PI-MWCNT composite film. Pt electrode was modified by coating with prepared PI-MWCNT composite film. Modified Pt electrode was used as PA sensor due to its selective membrane property in the presence of interfering substances for the electrochemical detection of PA. Electrochemical behaviour of paracetamol at the polyimide film modified Pt electrode was obtained by differential pulse voltammetry (DPV) and cyclic voltammetry (CV) method. It has shown that the modified electrode exhibits remarkable repeatability and precision in analytical paracetamol response as compared with other modified paracetamol electrodes. Comparing the responses of modified electrode with the unmodified Pt electrode, selectivity, sensitivity and stable responses significantly enhanced. A linear calibration plot having a correlation coefficient of 0.997 was obtained in the concentration range from 0.3 to 1.8 mM paracetamol. A linear calibration plot for low concentration area having a correlation coefficient of 0.999 was obtained in the concentration range from 0.002 to 0.05 mM paracetamol. Detection limit (LOD) and quantitative limit (LOQ) for paracetamol detection of PI-MWCNT modified electrode were calculated as 0.002 mM and 0.006 mM respectively. In addition, the presented method was applied for determination of PA in commercial tablets. The recovery efficiency of the PI modified electrode was obtained range of 96% and 102% for three different tablets. As a result; a simple, rapid, low cost, repeatable method showing good accuracy and precision (99.4%) has been developed for the selective and sensitive determination of paracetamol by prepared PI-MWCNT composite film modified electrode. (C) 2019 Elsevier Ltd. All rights reserved.