Tropolone-Based Treatments for Visualising Latent Fingermarks on Porous Surfaces

The work describes a new chemical means of visualising latent fingerprints (fingermarks) using tropolone. Tropolone reacts with amino acids within the fingermark residue to form adducts that absorb UV radiation. These adducts provide useful contrast on highly-fluorescent prous surfaces will illuminated with UV radiation. The conjugated seven-membered ring of the tropolone adduct can be reacted further diazonium salts, which is demonstrated here with formation of two dyes. The methodology is extremely rapid, occurring in minutes with mild heating, and can be applied before ninhydrin in a chemical detection sequence.