Fabrication ofa Novel MIL-88A@ZnCoFe LDH Compositefor the Sensitive Detection of Anticancer Drug Regorafenib in Biologicaland Pharmaceutical Samples

Regorafenib (RGR) is a highly selective diphenylurea multikinase inhibitor and anticancer agent that provides survival after standard therapies for metastatic colorectal cancer. To accurately and sensitively detect RGR, a novel MIL-88A, and ZnCoFe LDH composite was successfully synthesized and modified onto a glassy carbon electrode (MIL-88A@ZnCoFe LDH/GCE). The prepared electrode significantly improved the electron transfer between the electrode and the analyte, resulting in a more sensitive response to RGR oxidation under optimal conditions. Using differential pulse voltammetry (DPV), the developed electrochemical sensor exhibited a wide linear range from 0.01 to 16.4 μM, a low detection limit (LOD = 2.241 nM), and high selectivity in the presence of various interferences. The MIL-88A@ZnCoFe LDH/GCE was successfully applied for the detection of RGR in various samples, including human urine, human serum, and tablet dosage forms, achieving satisfactory recoveries ranging from 100.14 to 103.85%, thereby demonstrating its applicability in real-world applications.