New technique for locating fingerprints
Specially-engineered gold nanoparticles help locate hidden prints; the Secret Service calls it “revolutionary”
Just when we thought that traditional fingerprinting was dying art, researchers at the Hebrew University of Jerusalem prove us wrong by developing a new way of revealing hidden prints. Typically, such prints are located by coating the suspected surface with a watery suspension of gold nanoparticles, which stick to positively-charged molecules in the fingerprint before being developed with a solution of silver ions. This technique, however, is unstable and the technique is difficult to reproduce from one test to another. As an alternative, the Hebrew University team has replaced the gold solution with gold nanoparticles covered with long hydrocarbon chains and suspended in petrol ether. “They stick to the fingerprint residues through hydrophobic interactions, and can be developed with silver as before, producing high quality prints after just three minutes immersion time,” Chemical Science reported
A Secret Service forsensic expert described the new technique as “revolutionary.”
