The invention discloses a near-
infrared photosensitizer for specifically recognizing
fibroblast activation
protease (FAP-alpha) as well as a preparation method and application of the near-
infrared photosensitizer. A
cyanine derivative is used as a fluorescent parent
nucleus (ICyOH) of the
photosensitizer, the
fluorescence of the photosensitizer can be almost completely masked by modifying the photosensitizer, and after the photosensitizer reacts with FAP-alpha for 60 minutes, the
fluorescence intensity is rapidly enhanced, so that high sensitivity, good selectivity and anti-interference performance are shown. The ZGP-LL-ICy is a photosensitizer with a
cyanine structure, FAP-alpha
fluorescence enhancement and
high selectivity to FAP-alpha, the
reagent shows high selective response to FAP-alpha
enzyme, active ICyOH molecules with near-
infrared fluorescence are released under the action of enzymolysis, and tumor fluorescence imaging of
deep tissue penetration is achieved. Meanwhile, the activated ICyOH can generate cytotoxic
active oxygen under the illumination condition, and
photodynamic therapy on
pancreatic cancer is achieved. The
reagent has the advantages of low
background fluorescence,
deep tissue penetration, diagnosis and treatment integration and the like, and has important application value in the fields of early diagnosis and precise treatment of
pancreatic cancer.