Fluorine Grafted Cu7S4–Au Heterodimers for Multimodal Imaging Guided Photothermal Therapy with High Penetration Depth

We report the multifunctional nanocomposites (NCs) consisting of 19F-moieties grafted Cu7S4–Au nanoparticles (NPs) for negligible background 19F-magnetic resonance imaging (19F-MRI) and computed tomography (CT) imaging guided photothermal therapy. The localized surface plasmon resonance (LSPR) absorption can be reasonably tuned to the in vivo transparent window (800–900 nm) by coupling Au (<10 nm, LSPR ∼530 nm) with Cu7S4 (<15 nm, LSPR ∼1500 nm) into Cu7S4–Au heterodimers. The in vivo photothermal tests show that Cu7S4–Au show deeper light penetration with 808 nm irradiation, better photothermal efficacy, and less damage to normal tissues than Cu7S4 with 1500 nm irradiation. Moreover, compared to traditional 1H-MRI, the 19F-MRI based on these NCs demonstrates much better sensitivity due to the negligible background. This work offers a promising strategy for multimodal imaging guided photothermal therapy of deep tissue with good efficacy.