Ag-Sn@MOFs heterostructure enables ultrasensitive voltammetric determination of vismodegib in serum and urine

Accurate measurement of vismodegib (VIS) is essential for pharmacokinetic profiling, individualized dosing, and therapeutic drug monitoring. In this work, we report an Ag-Sn@MOFs heterostructure as a sustainable composite sensing interface for highly sensitive voltammetric determination of VIS. A simple solvothermal - reduction route yielded an integrated nanocomposite that synergistically combines the high conductivity and electrocatalytic activity of Ag nanoparticles with the high-surface-area, defect-rich architecture of Sn@MOFs. Multimodal characterization verified uniform immobilization of Ag nanoparticles on the Sn@MOFs scaffold and the formation of a stable, conductive interface. Owing to accelerated charge-transfer kinetics and enhanced VIS oxidation, the modified electrode delivered an ultralow limit of detection of 0.006 nM, high sensitivity of 14.782 µA nM^-1 cm^-2, and a wide linear range of 0.05-500 nM (R ² = 0.9974). Importantly, the sensor maintained excellent accuracy in complex matrices, providing recoveries of 95.6-107.6% with precision ≤3.29% RSD in spiked human urine and serum, demonstrating strong matrix tolerance. The combination of scalable, low-toxicity fabrication with robust selectivity and stability highlights the platform's potential for VIS therapeutic monitoring, pharmacokinetic studies, and translation toward point-of-care diagnostics.