Electrochemical Sensitive Determination of Chemotherapeutic and Immunomodulator Agent Methotrexate Enabled by Novel Graphitic Nano-Heterostructure Material

In this study, we report the electrochemical voltametric determination of methotrexate (MTX) chemotherapeutic and immunomodulatory agent with a novel graphitic nano-heterostructure (GNHS) material. In comparison with the previous studies, it shows a higher and enhanced peak transduction. In our research, our GNHS/CPE exhibits superior electrochemical oxidation and detection of MTX in buffer and biological fluids (plasma, urine) than bare Carbon Paste Electrodes (CPE). The synthesized GNHS material has been characterized using X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-visible absorption spectroscopy, scanning electron microscopy, Raman spectroscopy, cyclic voltammetry, square wave voltammetry, and electrochemical impedance spectroscopy. In addition, the electronic structure, adsorption energy, band gap, type of interaction, and stable configuration of the used GNHS/CPE have been studied by using density functional theory (DFT). Under optimized conditions, the GNHS/CPE platform showed a linear response for the MTX concentrations in Britton Robinson Buffer (BRB) solution, urine, and plasma with high recoveries and lower limit of detection (LOD) and Limit of Quantification (LOQ) in comparison to the current literature. In addition, reproducibility, stability, and selectivity studies show promising results for the modified GNHS/CPE electrode.