After adding 1 mL of 2.5 mg/mL TAT into the reaction bottle, 5 mg of EDC and NHS were added, and the solution was stirred at 25°C for 10 min. At the same time, 1 mL of PHSA-ICG solution and 200 μL of Tris-HCl (pH 8.8) solution were added to a new reaction bottle, and the mixture was stirred for 15 min in the dark. Subsequently, 1 mL of the activated TAT solution was added to the PHSA-ICG solution and the reaction was continued for 12 h in the dark. After the reaction, the product was dialyzed in ultrapure water for 8 h to obtain purified PHSA-ICG-TAT and stored in a refrigerator at 4°C.