Engineering Near‐Infrared Plasmonic Spiky Gold Nanostructures for Highly Efficient Surface‐Enhanced Raman Spectroscopy‐Guided Cancer Hyperthermia Therapy

Abstract Cancer phototheranostics utilizing plasmonic materials is attracting considerable interest due to its high spatiotemporal precision and specificity, remote controllability, superior therapeutic efficacy, and low systemic side effects. Exploring new plasmonic materials with excellent plasmonic and photothermal properties is at the frontier of cancer phototheranostics. Herein, this work systematically investigates the plasmonic and photothermal properties of spiky Au nanoparticles (NPs) with different shaped central cores – spiky Au nanosphere , spiky Au nanocube and spiky Au nanorod (AuNR). It is shown that the shape of the central core in spiky Au NPs has significant effects on their surface‐enhanced Raman spectroscopy (SERS) and photothermal performances, and spiky Au NPs of a spherical or cubic core are much superior for near‐infrared (NIR) SERS detection and hyperthermia therapy in comparison with spiky AuNRs. The spiky Au NP‐based SERS probes demonstrate the remarkable capability for SERS imaging of live cells and dynamic visualization of tumors in a 4T1 breast tumor mouse model after intravenous administration. Moreover, in vivo studies show exceptional hyperthermia therapeutic effects of such SERS probes against 4T1 breast tumors under NIR irradiation. This study suggests the potential utility of spiky Au NP‐based SERS probes for efficient SERS‐guided cancer hyperthermia therapy.