A researcher in Australia has developed a new way of collecting fingerprints, following a break-in at his home.
CSIRO materials scientist Dr Kang Liang explains that when he called the police they dusted the area for fingerprints but didn't find anything. "It got me thinking, what if I could apply some of the special materials I’d been working with in the lab to come up with a new, potentially better fingerprinting technique?"
The method he has come up with involves adding a drop of liquid containing metal organic framework (MOF) crystals to the surface being examined. Investigators using a UV light are able to see invisible fingerprints 'glow' in about 30 seconds.
The strong luminescent effect creates greater contrast between the latent print and surface, enabling higher resolution images to be taken for easier and more precise analyses.
Dr Liang believes that this technique could be used for more challenging evidence where conventional 'dusting' is not appropriate. "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," he said. "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."
CSIRO's study shows that tiny crystals rapidly bind to fingerprint residue, including proteins, peptides, fatty acids and salts, creating an ultra-thin coating that's an exact replica of the pattern.
"Because it works at a molecular level it's very precise and lowers the risk of damaging the print," Liang said.
CSIRO tested the method on nonporous surfaces including window and wine glass, metal blades and plastic light switches, with successful results.
Fingerprint identification has been used by law enforcement and forensic experts for over 100 years. Adding CSIRO's method to the mix could save time and costs and enhance investigations.
"When my house was broken into I saw how common practice fingerprinting is for police," Liang said. "Knowing that dusting has been around for a long time, I was inspired to see how innovative materials could be applied to create even better results.
"As far as we know, it's the first time that these extremely porous metal organic framework (MOF) crystals have been researched for forensics."
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.
The method could have other applications including new biomedical devices and drug delivery. CSIRO is now looking to partner with law enforcement agencies to apply the technique.
The research has just been published in the Advanced Materials journal.