Rattle-type Au@Cu2−xS hollow mesoporous nanocrystals with enhanced photothermal efficiency for intracellular oncogenic microRNA detection and chemo-photothermal therapy

The coupling of the localized surface plasma resonance (LSPR) between noble metals of Au, Ag and Cu and semiconductors of Cu2−xE (E = S, Se, Te) opens new regime to design photothermal (PT) agents with enhanced PT conversion efficiency. However, it is rarely explored on fabricating of engineered dual plasmonic hybrid nanosystem for combinatory therapeutic-diagnostic applications. Herein, rattle-type Au@Cu2−xS hollow mesoporous nanoparitcles with advanced PT conversion efficiency are designed for cellular vehicles and chemo-photothermal synergistic therapy platform. The LSPR coupling between the Au core and Cu2−xS shell are investigated experimentally and theoretically to generate a PT conversion efficiency high to 35.2% and enhanced by 11.3% than that of Cu2−xS. By conjugating microRNA (miRNA) gene probe on the surface, it can realize the intracellular oncogenic miRNA detection. After loading of anticancer drug doxorubicin into the cavity of the Au@Cu2−xS, the antitumor therapy efficacy is greatly enhanced in vitro and in vivo due to the NIR photoactivation chemo- and photothermal synergistic therapy. The rattle-type metal-semiconductor hollow mesoporous nanostructure with efficient LSPR coupling and high cargo loading capability will be beneficial to future design of LSPR-based photothermal agents for a broad range of biomedical application.