Carbonic anhydrases (CAs) are metalloenzymes that catalyze the conversion between carbon dioxide and bicarbonate.46 Carbonic anhydrase IX (CA IX) is overexpressed on the surface of a variety of cancer cells, and has been extensively used as a target in cancer treatment.47 Cu@IR783-CAI is composed of three main components: a NIR-II fluorescence reporter, a copper complex, and a CA inhibitor (CAI). Here, CA9 is linked to cancer.