Scientists in China have discovered a method for visualising latent fingerprints found at the scene of a crime, which they say is very simple, rapid, does not require professional forensic treatment and does not destroy the print.
Bin Su and co-workers from Zhejiang University, Hangzhou, noticed that the conjugated compound tetraphenylethene (TPE) adhered to the greasy ridges of fingerprints via a hydrophobic interaction. TPE is non-fluorescent in acetonitrile solution, but when light with a 365nm wavelength is shone onto the solution, the compound can lose the extra energy by rotating. However, when TPE sticks to the fingerprint, its molecules clump together (or aggregate). The aggregated molecules can no longer rotate, so instead, they release the energy as light. This phenomenon is known as aggregation induced emission (AIE) and has been used in sensors, but never as a means of detecting fingerprints.
Read the full story in Chemistry World
Link to journal article
Aggregation induced emission for the recognition of latent fingerprints
Yan Li , Linru Xu and Bin Su
Chem. Commun., 2012, 48, 4109-4111, DOI: 10.1039/C2CC30553D