Self-Assembly MoS₂@MnO₂ Nanoflowers for the Fluorescence/Magnetic Resonance Dual-Modal Sensing of H₂O₂ and Photothermal Therapy

The functions of bioimaging and photothermal therapy integrated into a theranostic nanosystem to prove its diagnostic and therapeutic capabilities are desirable. The versatile molybdenum disulfide (MoS 2 ) dots doped with manganese dioxide (MnO 2 ) nanoflowers (MoS 2 @MnO 2 NFs) were designed for the dual-modal fluorescence/magnetic resonance (MR) sensing/imaging of intracellular H 2 O 2, as well as thermal/MR imaging-guided photothermal therapy in vivo . The MnO 2 nanosheets in MoS 2 @MnO 2 NFs acted as an H 2 O 2 -mediated initiator, exhibiting fluorescence recovery and Mn 2+ -related MR signal enhancement through specific H 2 O 2 -induced MnO 2 sheet degradation. Under the optimal experimental conditions, a dual-modal fluorescence/MR sensor was used to quantitatively detect and image H 2 O 2 and intracellular H 2 O 2, with a limit of detection (LOD) of 0.09 μM. Simultaneously, thermal-responsive MoS 2 @MnO 2 NFs showed robust photothermal cytotoxicity toward cancer cells upon near-infrared (NIR) irradiation, allowing it to serve as a therapeutic drug for thermal/MR imaging-guided photothermal therapy in vivo . This integrated theranostic nanosystem demonstrated its power for multimodal bioimaging and enhanced therapeutic therapy while reducing biotoxicity in mice.