A novel electrochemical sensor based on GQDs-PANI/ZnO-NCs modified glassy carbon electrode for simultaneous determination of Irinotecan and 5-Fluorouracil in biological samples

Graphene quantum dots-polyaniline/zinc oxide nanocomposites (GQDs-PANI/ZnO-NCs) was successfully synthesized and employed as excellent modifier to construct a novel and highly selective electrochemical sensing platform for the simultaneous determination of two important anticancer drugs, Irinotecan (CPT-11), and 5-Fluorouracil (5-FU). FTIR, XRD, TEM, and FE-SEM were used to characterize the synthesized NCs. A detailed study by electrochemical methods such as CV, EIS, and DPV were performed to clarify the electrocatalytic properties of GQDs-PANI/ZnO-NCs and preparation process of the modified glassy carbon electrode (GCE). The experimental conditions for CPT-11 and 5-FU detection were optimized by Taguchi L-25 orthogonal array design, and under the optimal condition, the GQDs-PANI/ZnO-NCs/GCE presented a linear response in the ranges 0.1-25.0 and 0.1-50.0 mu M and low detection limits of 0.011 and 0.023 mu M, for CPT-11 and 5-FU, respectively. The reliability of the proposed sensor was verified by precise and sensitive simultaneous determination of CPT-11 and 5-FU in the pharmaceutical formulation and biological samples.