A novel electrochemical sensor based on functionalized glassy carbon microparticles@CeO2 core-shell for ultrasensitive detection of breast anticancer drug exemestane in patient plasma and pharmaceutical dosage form

Abstract A novel core-shell structure composed of functionalized glassy carbon microspheres (f-GC) as core and CeO2 nanoparticles as shell was successfully synthesized by using hydrothermal process (H). The morphology and composition of the as-prepared f-GC@CeO2-H core-shell microspheres were characterized using XRD, SEM, TEM, EDX and mapping analysis. Electrochemical investigations revealed that f-GC@CeO2-H modified carbon rod electrode (CRE) possessed intriguing properties towards electrosensing breast anticancer exemestane (EXE) due to the synergistic interactions between f-GC core and CeO2 nanoparticles shell. The newly sensor f-GC@CeO2-H/CRE exhibited a high electrocatalytic activity towards electro-reduction of EXE and under the optimal conditions, the linear range of EXE was 0.05 µM to 10.9 µM with a low limit of detection of 18 nM. Furthermore, electrosensing of the steroidal aromatase inhibitor EXE in the presence of the non-steroidal aromatase inhibitor letrozole (LTZ) was achieved without anti-interference ability. The developed sensor shows admirable sensitivity in the detection of the two aromatase inhibitors simultaneously in biologically relevant samples. Finally, the proposed sensor was very effective for EXE determination from commercial tablets, human fluids and clinical patient blood.