A Multifunctional Nanoplatform with UCNP/Au Nanoprism Wrapped in Mesoporous MnO₂ for Photothermal Conversion and Drug Release

Lanthanide-doped upconversion nanoparticles (UCNPs) can achieve multiple emissions and have garnered significant attention in accurate diagnostics over the past few years. Herein, multifunctional core–shell nanoplatforms (UCNP/Au@MnO2 NPs) were developed by combining Au, UCNP and mesoporous MnO2. Under near-infrared (NIR) laser irradiation, the UCNP/Au@MnO2 NPs achieved excellent photothermal conversion and photoluminescence properties. The UCNP/Au@MnO2 NPs have demonstrated exceptional performance in fluorescence quenching and recovery, as MnO2 can serve as both a fluorescence quencher and a GSH recognizer. Moreover, the mesoporous MnO2 shell of the UCNP/Au@MnO2 NPs served as an effective nanocarrier. A comprehensive analysis of drug release kinetics and mechanisms revealed that the UCNP/Au@MnO2 NPs exhibited sensitive GSH- and NIR-responsive drug release behavior. The cumulative drug release reached up to ca. 94.52%, with the release profile being dependent on both GSH concentration and NIR laser irradiation. Thus, the work highlights the potential of UCNP/Au@MnO2 NPs as a versatile platform for applications, such as smart photoluminescence, photothermal conversion, and controlled drug release.