Color-tunable, water-stable room-temperature phosphorescent carbon dot-based Nanoplatform for intelligent tumor theranostics with self-monitoring of drug release.

Carbon dot (CD)-based room-temperature phosphorescent (RTP) materials have undergone rapid development, yet the underwater multicolor RTP modulation of materials based on CDs with an identical structure has not been reported to date. Limited by the absence of specific morphology or simple low-dimensional morphologies, most underwater RTP materials are also confined to single applications. This work addresses these gaps by constructing containerized hollow mesoporous silica (HMSs) shells encapsulating the same CDs (designated as EPCDs), achieving precise underwater RTP emission regulation from 500 nm to 670 nm via concentration tuning, and extending the system to intelligent tumor theranostics. Unlike conventional solid matrices, the HMSs shell provides stable water-resistant RTP and forms controllable nanodrug carriers EPCDs@HMSs (designated as EH). Oxidized hyaluronic acid (OHA) seals the pores of aminated EH (designated as EHN) via the Schiff base reaction, thereby endowing the resultant EHN-OHA system (designated as EHO) with tumor-targeting capability and pH-responsive drug release property. Furthermore, Förster resonance energy transfer between EPCDs and doxorubicin (DOX), combined with DOX's aggregation-caused quenching effect, allows real-time monitoring of intratumoral drug concentration. Applied in mouse models, this integrated platform demonstrates excellent antitumor efficacy, offering a novel strategy for water-resistant CD-based RTP materials in real-time theranostic monitoring.