1,8-Diazafluoren-9-one (DFO) is an aromaticketone first synthesized in 1950. It is used to find fingerprints on porous surfaces.[1][2] It makes fingerprints glow when they are lit by blue-green light.[2]
DFO reacts with amino acids present in the fingerprint to form highly fluorescent derivatives. Excitation with light at ~470 nm results in emission at ~570 nm.[2]
^ abcPounds, C. Anthony; Grigg, Ronald; Mongkolaussavaratana, Theeravat (1 January 1990). "The Use of 1,8-Diazafluoren-9-one (DFO) for the Fluorescent Detection of Latent Fingerprints on Paper. A Preliminary Evaluation". Journal of Forensic Sciences. 35 (1): 169–175. doi:10.1520/JFS12813J.