Plant Polyphenol‐Assisted Green Synthesis of Hollow CoPt Alloy Nanoparticles for Dual‐Modality Imaging Guided Photothermal Therapy

Theranostic nanomedicines that integrate diagnostic and therapeutic moieties into a single nanoscale platform are playing an increasingly important role in fighting cancer. Here, a facile and green synthetic strategy for hollow CoPt alloy nanoparticles (HCPA‐NPs) using plant polyphenols as assisted agents is reported for the first time. This novel strategy enables size‐controlled synthesis of HCPA‐NPs through the control of the molecular sizes of polyphenols. It is also a versatile strategy for synthesizing other hollow alloy nanoparticles with various metal compositions due to the diverse metal‐chelating ability of the polyphenols. Further studies show that HCPA‐NPs have good biocompatibility and can be successfully implemented for magnetic resonance and photoacoustic dual‐modal imaging guided photothermal therapy. This work brings new insights for the green synthesis of hollow nanoparticles and extends these biocompatible nanoparticles for theranostic applications.