A new sensor consisting of Ag-MWCNT nanocomposite as the sensing element for electrochemical determination of Epirubicin

Here, we introduce a new electrode comprising silver decorated multiwall carbon nanotube (Ag-MWCNT) as the sensing element for voltammetric investigation of anticancer drug Epirubicin (EP) in human whole blood, urine and injection. Field emission scanning electron microscopy (FE-SEM), TEM, EDX and XRD methods were used to study the surface structure and topography of the modified electrode. We used electrochemical impedance spectroscopy (EIS) as a powerful tool to analyze the electrochemical properties of the new electrode. This modified electrode was applied for investigation of EP by cyclic voltammetry (CV) and square wave voltammetry (SWV) in an acetate buffer solution as a suitable supporting electrolyte (pH 1.5 - 6.8). The CV of EP in the potential range of -1.0 to 1.0 V showed reversible redox peaks that were dependent on pH. We optimized the conditions needed for practical application of the new electrochemical sensor, for which the redox peak current at pH 4.7 was linearly proportional to the concentration of EP in the range of 0.003 - 0.25 μM with a detection limit of 1.0 × 10-3 μM (RSD < 5%) after 20 min of accumulate time by SWV. This sensor is suitable for the analysis of trace amounts of EP in pharmaceuticals, blood or urine samples.