Aqueous Topological Synthesis of Au@semiconductor Core–Shell Nanocrystals with Morphology and Composition Engineering

Core–shell nanocrystals (C–S NCs) are an essential class of materials whose structural engineering has attracted wide attention due to their tunable optical and electrical properties, especially noble metal@semiconductor (NMS) C–S NCs with flexible plasmon-exciton coupling. Due to their diverse critical applications, especially aqueous biological applications, herein we propose an aqueous topological strategy enabled by cation exchange reactions (CER) to synthesize various plasmonic Au@semiconductor C–S NCs, in which environmentally friendly triphenylphosphine (TPP) is used as an initiator instead of inflammable tributyl phosphine (TBP). The introduction of the milder, solid TPP facilitated a new aqueous CER strategy for synthesizing Au@semiconductor NCs with tailored chalcogenide compositions and morphologies. For example, the as-synthesized Au@ZnS C–S NRs had better absorption and biocompatibility and exhibited excellent photodynamic therapy efficacy.