A Water-Dispersible Perovskite-Magnetic Nanocomposite Platform for Efficient Dual-Modal Fluorescence/MR Imaging.

Lead halide perovskite quantum dots (PQDs) exhibit outstanding optical properties, including high photoluminescence quantum yield, narrow emission bandwidth, and tunable emission wavelengths. However, structural instability and susceptibility to degradation in aqueous environments significantly limit their applicability in biological imaging systems. Therefore, the development of PQD-based imaging platforms with excellent optical performance and enhanced aqueous stability remains a critical challenge. Herein, a water-dispersible nanocomposite nanoimaging platform CsPbBr3-Fe3O4@SA@DSPE-mPEG (CPB-Fe@SA@DSPE) was successfully synthesized by employing stearic acid (SA) as a hydrophobic shell and amphiphilic molecule DSPE-mPEG as a hydrophilic layer, enabling dual-modal fluorescence and magnetic resonance imaging (MRI) for tumor diagnostics. This platform demonstrates remarkable water dispersibility and stability, retaining 42.8% of its initial fluorescence intensity after 37 days in an aqueous medium. In addition, it exhibits superparamagnetic behavior with a saturation magnetization of 0.96 emu/g. In vitro experiments further confirmed its dual-mode imaging capability in tumor models, underscoring its potential in precision diagnostics. Therefore, this study provides a promising strategy to overcome the intrinsic limitation of PQDs in biomedical imaging and broadens the scope of PQD-based applications.