1：Experimental Design and Method Selection:

The study involved designing and synthesizing phenazine-cyanine dyes with acceptor-donor-acceptor structures to achieve near-infrared absorption for PA imaging and PTT. Methods included organic synthesis, nanoparticle formation with HSA, and in vitro and in vivo testing.

2：Sample Selection and Data Sources:

Dyes PH-1 and PH-2 were synthesized; nanoparticles PH-1@HSA and PH-2@HSA were prepared. In vitro tests used 4T1 cells; in vivo tests used nude mice with subcutaneous tumors.

3：List of Experimental Equipment and Materials:

Materials included phenazine, indole salts, HSA, DMSO, PBS buffer; equipment included NMR spectrometer, mass spectrometer, UV-vis spectrophotometer, DLS, TEM, SEM, MTT reader, confocal microscope, thermal imager, laser.

4：Experimental Procedures and Operational Workflow:

Synthesis of dyes via reduction, substitution, and condensation reactions; assembly with HSA to form nanoparticles; characterization of optical properties, size, stability; in vitro photothermal and cytotoxicity assays; in vivo PA imaging and PTT in mice.

5：Data Analysis Methods:

Data analyzed using NMR, MS, UV-vis spectra, DLS for size, TEM for morphology, MTT assay for cytotoxicity, thermal imaging for temperature, and PA signal intensity measurements.