Magnetic-Optical Dual-Modality Imaging Monitoring Oxaliplatin through the Crystalline Mn-Metal–Organic Framework Sensor

To support image-assisted evaluation of anticancer drugs in biological settings, functional sensing materials are needed to integrate sensitive molecular detection with imaging-compatible readouts. Oxaliplatin (OHP) is widely used in chemotherapy, and accurate OHP assessment in biological matrices remains important for dosage optimization and toxicity management. Herein, a nanosized Mn-MOF was prepared as a fluorescence sensor and MRI-responsive platform for OHP-associated detection. The structure, morphology, elemental distribution, and Mn surface electronic state of the Mn-MOF were characterized by XRD, SEM, AFM, EDS mapping, XPS, and DLS. Mn-MOF showed limited dialyzable Mn leakage, and retained fluorescence stability and MRI signal stability during 28 days of storage. As a T 1 MRI contrast platform, Mn-MOF exhibited a longitudinal relaxivity ( r 1 ) of 6.38 mM –1 s –1 at 3.0 T and showed OHP-dependent T 1 signal attenuation over the tested OHP concentration range of 0.5–10 mM. Preliminary in vivo MRI experiments showed liver and kidney T 1 enhancement after intravenous Mn-MOF administration and OHP-associated attenuation of the Mn-MOF-enhanced signal. In fluorescence mode, the Mn-MOF nanosensor exhibited concentration-dependent quenching toward OHP in ultrapure water over 0.33 fM–18.2 μM, with a calibration-model-based estimated limit of detection (LOD) of 41.1 aM under the stated Mn-MOF-assisted fluorescence sensing conditions. The sensor also showed selectivity under the tested interference conditions, spiked-rabbit-serum calibration and recovery performance, and 28-day fluorescence response stability. Hemolysis, H&E staining, KGN and HK-2 cell-viability assays indicated preliminary hemocompatibility and cytocompatibility under the tested conditions. This dual-modal design provides a preliminary strategy for integrating optical OHP sensing with MRI readout in a single Mn-MOF platform.