CSIRO has developed a new technique for identifying fingerprints by making them glow under ultraviolet light.
The technique, developed by engineer Dr Kang Liang, involves adding a drop of liquid containing metal organic framework (MOF) crystals to the surface containing the print.
Within 30 seconds the crystals bind to fingerprint residue, including proteins, peptides, fatty acids and salts, creating an ultrathin coating that’s an exact replica of the pattern.
The MOF crystals have a number of benefits in that they are cheap, react quickly and can emit a bright light. The technique doesn’t create any dust or fumes, reducing waste and risk of inhalation.
Dr Liang said the technique could be used for more challenging evidence where conventional ‘dusting’ is not appropriate.
“Because it works at a molecular level it’s very precise and lowers the risk of damaging the print,” he said.
“While police and forensics experts use a range of different techniques, sometimes in complex cases evidence needs to be sent off to a lab where heat and vacuum treatment is applied. Our method reduces these steps, and because it’s done on the spot, a digital device could be used at the scene to capture images of the glowing prints to run through the database in real time.”
For Liang, it’s also personal. He got interested in the subject watching police dusting for fingerprints after a break-in at his home.
“Knowing that dusting has been around for a long time, I was inspired to see how new innovative materials could be applied to create even better results,” he said.
“As far as we know, it’s the first time that these extremely porous metal organic framework crystals have been researched for forensics.”
He has tested the method on a range of nonporous surfaces including window and wine glass, metal blades and plastic light switches, with successful results.
He believes the method could have other valuable applications including new biomedical devices and drug delivery and says CSIRO is now looking to partner with law enforcement agencies to apply the technique.
His research is published in the journal Advanced Materials.
The technique used on knife blades. Different colours are achieved by adjusting the chemistry of the liquid. Image: CSIRO.