An innovative strategy for Gefitinib quantification in pharmaceutical and plasma samples using a graphene quantum dots-combined gold nanoparticles composite electrochemical sensor

An innovative methodology is proposed for quantifying Gefitinib (GFT) using an electrochemical sensor constructed from a composite of graphene quantum dots (GQDs) and gold nanoparticles (AuNPs). GQDs were synthesized from graphite, preserving graphene’s large surface area and excellent electron transfer capabilities while enhancing dispersibility. The combination of GQDs with AuNPs resulted in an AuNPs@GQDs composite, which was used to construct the sensor. The synthesized nanomaterials were characterized using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and the electrochemical performance of the sensor was evaluated via cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Under optimized conditions, the sensor displayed a linear calibration curve for GFT detection within the range 0.01 to 10.0 µM, with a limit of detection (LOD) of 0.005 µM (S/N = 3). The sensor demonstrated excellent anti-interference properties and stability in tests using pharmaceutical formulations and plasma samples. Compared to chromatographic methods, the sensor exhibited similar accuracy and recovery. Its easy fabrication and high sensitivity make it a promising tool for pharmaceutical analysis and clinical therapeutic drug monitoring.