Glowing fingerprints to help nail criminals

Sydney: An Australian scientist has developed a liquid adding a drop of which to a surface can make invisible fingerprints glow in about 30 seconds.

Researchers believe that the new technique could save time and cost of investigations.

"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," said Kang Liang, a materials scientist at the Commonwealth Scientific and Industrial Research Organisation (CSIRO) in Australia's Victoria state.

"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," Liang added.

By adding a drop of the liquid containing crystals to surfaces, investigators using ultraviolet light are able to see invisible fingerprints glow in less than a minute, the study said.

The liquid contains metal organic framework (MOF) crystals that bind to the residue left behind in a fingerprint, including fatty acids, proteins, peptides and salts, creating an ultra thin coating that is an exact replica of the pattern.

"Because it works at a molecular level it is very precise and lowers the risk of damaging the print," Liang said.

The method was tested on non-porous surfaces including window and wine glass, metal blades and plastic light switches, with successful results.

Fingerprint identification has been used as a key method by law enforcement and forensic experts for over 100 years.

Adding the new method to the mix could save valuable time, costs and enhance investigations, noted the research published in the journal Advanced Materials.