This invention relates to the field of bacterial infection treatment technology, and discloses an
enzyme-responsive probe, its preparation method, and its applications. The probe of this invention constructs an
enzyme-responsive "
prodrug" structure by introducing
cephalosporin derivative
linker units that can be specifically cleaved by β-
lactamases onto a hemicyanine optical framework. This structure remains optically and therapeutically
inert in normal tissues, but is selectively activated at the site of infection by
drug-
resistant bacteria. When the probe contacts multidrug-
resistant bacteria that overexpress β-
lactamases, the
linker units undergo enzymatic cleavage, releasing hemicyanine active molecules with near-
infrared fluorescence emission and highly efficient
photothermal conversion capabilities, achieving high-contrast
fluorescence imaging and controllable photothermal sterilization of the infection focus. The probe of this invention has a simple synthetic
route, mild conditions, and reliable
purification methods, making it suitable for large-scale preparation, especially for the precise diagnosis and targeted photothermal synergistic treatment of superficial tissue infections such as bacterial
keratitis.