A Two-Photon Zn(II) Complex Photosensitizer with pH/Viscosity Dual Response for Enhanced Tumor Therapy

In recent years, an increasing number of studies have shown that novel metal complexes with bio-imaging capabilities could enhance precision oncology, particularly through optimized photosensitizer (PS) design for subcellular organelle targeting photodynamic therapy (PDT). Based on this, we successfully developed a two-photon (TP) fluorescent Zn(II) complex, LIFM-ZY-3, characterized by the specifical targeting capability of lysosome. This complex was capable of monitoring dual changes in pH and viscosity. Additionally, our findings indicated that the complex could generate multiple reactive oxygen species (ROS), including singlet oxygen (¹O₂), hydroxyl radicals (•OH), and superoxide anion radicals (O₂^-) under white light irradiation in vivo and in vitro. These findings underscored the remarkable versatility of LIFM-ZY-3 as an advanced multifunctional PS for both microenvironment monitoring and tumor therapy.