Symmetrically Fluorinated D‐π‐A Structured Cyanine Dye for Highly Efficient NIR‐II Imaging‐Guided Cancer Phototheranostics

Near-infrared-II (NIR-II) fluorescence imaging-guided photothermal therapy (PTT) represents a cutting-edge approach for precise tumor diagnosis and treatment, providing real-time therapeutic efficacy evaluation. However, a significant challenge lies in the creation of phototheranostic agents that provide robust imaging and efficient photothermal conversion. To address this, a donor-π-acceptor (D-π-A) structure heptamethine cyanine derivative, IR1116, that confers a strong intramolecular charge transfer effect is developed. To enhance its applicability, IR1116 is formulated with DSPE-PEG to create a water-dispersible NIR-II phototheranostic nanoheater, NP