Nir‐Ii Emissive Superoxide Radical Photogenerator for Photothermal/photodynamic Therapy Against Hypoxic Tumor

Abstract Due to the “Achilles' heels” of hypoxia, complicated location in solid tumor, small molecular photosensitizers with NIR‐II fluorescence, type‐I PDT, and PTT have attracted great attention. However, these photosensitizers are still few but yet challenging. Herein, we present an “all in one” NIR‐II A‐D‐A fused‐ring photosensitizer, Y6‐Th, for the in‐depth diagnosis and efficient treatment of cancer. Benefiting from the strong intramolecular charge transfer, promoted highly efficient intersystem crossing, largely π‐conjugated fused‐ring structure, and reduced planarity, the fabricated nanoparticles (Y6‐Th NPs) could emit NIR‐II fluorescence with the peak located at 1020 nm, exclusively generate O 2 • − for type‐I PDT and display excellent PTT performance under an 808 nm laser stimulation. These characteristics make Y6‐Th a distinguished NIR‐wavelength‐triggered phototheranostic agent, which could effectively therapy the hypoxic tumor using NIR‐II fluorescence‐guided type‐I PDT/PTT. This work provides a valuable guideline for fabricating high‐performing NIR‐II emissive superoxide radical photogenerators. This article is protected by copyright. All rights reserved