Electrochemical Sensor Based on Functionalized Multiwalled Carbon Nanotubes, Domperidone Determination, DNA Binding and Molecular Docking

An electrochemical sensor based on modification of carbon paste electrode by the functionlized MWCNT (f-MWCNT/CPE) was prepared for determination of Domperidone in formulation and in human serum. f-MWCNTs were prepared by a simple surface oxidization of the pristine MWCNTs using a famous, less expensive and less vigorous KMnO4. The f-MWCNTs were characterized using FTIR spectra, TEM, BET N2 sorption isotherms and TGA. Point of zero charge of pristine and oxidized MWCNTs was also determined. The surface morphology and charge transfer resistance of the bare and f-MWCNT/CPEs were investigated using SEM and EIS. The detection limit (4.68 × 10−11 M) indicates the sensitivity of the developed electrode for trace assay of Domperidone in biological fluids. The binding interactions of Domperidone with DNA and the mode of this binding have been investigated using cyclic voltammetry, UV-vis spectrophotometry and molecular docking studies. The estimated binding free energy (-20.47 KJmol−1) by Autodock was comparable to the experimental free energy (-25.82 KJmol−1) in the cyclic voltammetric analysis. The minor groove-binding mode of interaction was also supported by docking simulation studies. The higher binding constant value (8.77 × 104 M−1) might be sufficient to interfere with DNA replication and thus, Domperidone can be used as an anticancer therapy.