A Disposable Carbon Nanotubes-screen Printed Electrode (CNTs-SPE) for Determination of the Antifungal Agent Posaconazole in Biological Samples

For the first time, the use of carbon nanotubes was exploited for the development of a sensitive electrochemical method for determination of the newly antifungal posaconazole (POS). The electrochemical activity of POS was investigated at the surface of multi-walled nanotubes (MWNTs) modified electrode. The cyclic voltammograms showed a sharp oxidation peak at potential around 671mV vs. Ag/AgCl. To reach the assay optimization, factors affecting the method sensitivity have been investigated, such as types of carbon nanotubes and its concentration in the electrode matrix, type of supporting electrolyte, pH, accumulation time and scan rate. A good linear relationship was obtained within the concentration range from 32-1280ng/ml with the limit of detection and quantification of 11ng/ml and 33ng/ml, respectively. The proposed method was successfully applied for the determination of POS in its commercial dosage form, spiked human plasma samples, and dried blood spots. The in vivo results obtained were also used to study the pharmacokinetics of POS in human plasma. The results obtained were validated and found to be in accordance with those obtained by the reference methods.