Comparative Electrochemical Investigation of Pelitinib at BDDE and PGEE: Mechanistic Insights, Surfactant Effects, and Application to Serum Samples

Pelitinib (PEL) is an irreversible tyrosine kinase inhibitor targeting the human epidermal growth factor receptor (HER) family and is generally utilized in the treatment of HER2-positive cancers. Despite its clinical significance, the electrochemical behavior of PEL has not been reported so far. In this research, the electrochemical features of PEL were systematically investigated for the first time at boron doped diamond electrode (BDDE) and pyrolytic graphite edge electrode (PGEE). Cyclic voltammetry (CV), differential pulse voltammetry (DPV), and adsorptive stripping voltammetry (AdSV) were utilized to elucidate the oxidation mechanism and to develop sensitive electroanalytical methods for PEL determination. The oxidation of PEL was found to be irreversible at both electrodes. Scan rate studies revealed a diffusion-controlled process at BDDE, whereas a mixed diffusion–adsorption controlled behavior was observed at PGEE. The Ep–pH relationship indicated a proton-coupled electron transfer mechanism, and distinct breakpoints observed were associated with the pKa values of PEL. The effect of surfactants showed electrode-dependent behavior. Under optimized conditions, the DPV method at BDDE exhibited a linear response over the concentration range of 0.5–7.0 μM with a detection limit of 160.00 nM, whereas the AdSV method at PGEE provided a significantly improved sensitivity with a linear range of 0.003–0.3 μM and a remarkably low detection limit of 0.80 nM. In serum samples, the methods retained good analytical performance, with LOD values of 223.00 nM (BDDE) and 4.60 nM (PGEE), along with satisfactory recovery results. These findings demonstrate that the proposed electrochemical approaches offer simple, sensitive, and cost-effective alternatives for the determination of PEL in pharmaceutical and biological samples.