Photodynamic therapy (PDT) as an appealing modality has been used to treat various malignant tumours. Compared with conventional PDT treatment activated by ultraviolet or visible light, near infrared (NIR) light triggered PDT possessing deeper penetration to lesion area and lower photodamage to normal tissue holds great potential for deep-seated tumor. To address these obstacles for PDT treatment, we firstly used aza-indole to modify pentamethine dyes to facilitate a large bathochromatic shift of the absorption maximum from 650 nm to 730 nm in the photo-therapeutic window. Interesting, BY-Br have higher molar extinction coefficient than BY-H, allowing BY-Br to absorb more light for enhance its therapeutic effect. Meanwhile, the introduction of bromine atoms has been enhanced reactive oxygen species generation (ROS) after laser irradiation. Furthermore, the new photosensitizer, BY-Br could specifically target to mitochondria, and substantial kill tumor cells through apoptotic pathway upon irradiation.

光动力疗法（PDT）作为一种有吸引力的方式已被用于治疗各种恶性肿瘤。与通过紫外线或可见光激活的常规PDT治疗相比，近红外（NIR）光触发的PDT具有更深的穿透病变区域和较低的对正常组织的光损伤的潜力，可深层治疗肿瘤。为了解决PDT处理的这些障碍，我们首先使用氮杂吲哚修饰五甲胺染料，以促进光疗窗中吸收最大值从650 nm到730 nm的较大的红移。有趣的是，BY-Br的消光系数比BY-H高，这使得BY-Br吸收更多的光以增强其治疗效果。同时，溴原子的引入增强了激光辐照后活性氧的产生（ROS）。此外，新型光敏剂BY-Br可以特异性靶向线粒体，并在照射后通过凋亡途径大量杀死肿瘤细胞。