Hydroxyl radical-activated NIR-II hemicyanine photosensitizer for selective photodynamic cancer therapy

Abstract

A water-soluble and heavy-atom-free hemicyanine photosensitizer H-WBHcy, specifically activated by •OH (a tumor biomarker), was synthesized for the first time. H-WBHcy could sensitively respond to •OH (LOD = 8.7 nM), showing redshifted absorption from 500 nm to 694/765 nm as well as fluorescence emission at 910 nm. Meanwhile, •OH was able to trigger the oxidized product of H-WBHcy to further produce 1 O 2 under 808 nm laser irradiation, which could significantly inhibit the growth of cancer cells. We believe this work provides a strategy to develop activatable near-infrared photosensitizers for precise photodynamic therapy.