Water Soluble and Bright Luminescent Cesium Lead Bromide Perovskite Quantum Dot-Polymer Composites for Tumor-Derived Exosomes Imaging

Cesium-lead-halide perovskite quantum dots (PQDs), are a highly promising class of next-generation optical material for bio-imaging applications. Herein, we present a nanocomposite strategy for the de-sign of water soluble, highly luminescence CsPbBr3 PQD nanocomposites without modifying the crystal symmetry and photoluminescence (PL) property. Water soluble PQDs are reproducibly synthesized via encapsulating CsPbBr3 PQDs with polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (PS-PEB-PS) and poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol (PEG-PPG-PEG). In the reported design, the polystyrene triblock polymers strongly interact with the hydrophobic parts of PQDs and the water-soluble PEG moiety acts as protection layer to effectively prevent degradation of PQDs in water. Outer shell PEG layer also helps to develop biocompatible PQDs. Reported data indicate that encapsulating CsPbBr3 PQDs with polymer helps to improve the photoluminescence quantum yield (PLQY) fr...