AgAuSe-COOH (1000 nm) is a fluorescent quantum dot that emits fluorescence in the near-infrared II region, with an emission peak reaching 1000 nm. AgAuSe-COOH (1000 nm) has the advantages of narrow band gap, large Stokes shift, and good photostability. AgAuSe-COOH (1000 nm) can bind proteins, antibodies , peptides , PEG, etc., and can be widely used in the field of biological imaging.