FD-1080 free acid, an NIR-II region fluorophore (Ex=1064 nm, Em=1080 nm), facilitates in vivo imaging [1].

FD-1080 exhibits enhanced photostability when subjected to sustained laser exposure. Its quantum yield is initially 0.31%, but this increases to 5.94% upon forming complexes with fetal bovine serum (FBS), thereby creating FD-1080-FBS complexes [1].

FD-1080 excitation at 1064 nm in the NIR-II range exhibited enhanced tissue penetration and improved imaging resolution over the 650-980 nm NIR spectrum. This capability facilitated deep-tissue, high-resolution in vivo imaging of the vasculature in the left hindlimb, abdomen, and brain, effectively penetrating intact skin, tissue, and bone. Additionally, FD-1080 enabled the quantification of respiratory rates by dynamically imaging the craniocaudal motion of the liver in both awake and anesthetized mice [1].