IR-813 p-Toluenesulfonate is widely used in the field of biomedical imaging, particularly in near-infrared (NIR) fluorescence imaging. Its strong absorption and emission in the NIR range make it an excellent contrast agent for visualizing deep tissues and organs in vivo. This chemical is often employed in cancer research for tumor detection and monitoring, as it can selectively accumulate in tumor tissues, enhancing imaging precision. Additionally, it is utilized in photodynamic therapy, where it acts as a photosensitizer to generate reactive oxygen species upon light irradiation, effectively targeting and destroying cancer cells. Its stability and biocompatibility further support its application in various diagnostic and therapeutic procedures.