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

Abstract

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.