Fingerprints are the impressions le by raised portions of the friction skin, which feature a series of lines corresponding to ridges and grooves. It is the pattern of these ridges and grooves that renders each ngerprint unique. Since the late 19th century, ngerprints have been used in forensic investigations to establish the identity of an individual, and continue to be an important tool in our daily life for many other purposes, such as access control, safety inspection, and individual credentials. 1, 2 The most common form of ngerprint evidence is latent ngerprints (LFPs), which are present but invisible to the naked eye and require some means of “development” to enhance the visual contrast between the prints and their backgrounds. 3

The past two decades have witnessed great innovation of the instrumental and synthetic techniques successfully employed for ngerprint detection. For example, chemical imaging techniques utilizing Raman, 4, 5 FTIR, 6–8 and mass spectrometry, 9–11 have signi cantly improved the study of ngerprint composition because of their ability to identify and map the compounds present in ngerprint residues. Additionally, the application of nanoparticles (NPs), including gold NPs, 11–15 TiO2 particles, 16 nano-structured ZnO, 17 and quantum dots, 18, 19 for ngerprint detection has also attracted considerable interest. 3