The dye in action. Credit: University of Bath
Scientists have developed a water soluble, non-toxic fluorescent spray that makes fingerprints visible in just a few seconds, making forensic investigations safer, easier and quicker.
Traditional forensic methods for detecting fingerprints either use powders that have the potential to harm DNA evidence, or environmentally damaging petrochemical solvents.
The new dye spray, developed by scientists at the Shanghai Normal University (China) and the University of Bath (UK), is water-soluble, exhibits low toxicity and enables rapid visualization of fingerprints at the crime scene.
The team created two different colored dyes – called LFP-Yellow and LFP-Red – which bind selectively with the negatively charged molecules found in fingerprints, locking the dye molecules in place and emitting a fluorescent glow that can be seen under blue light.
The dyes are based on a fluorescent protein found in jellyfish, called Green Fluorescent Protein (GFP), which is used extensively by research scientists to visualize biological processes. This means the dyes are biologically compatible and don’t interfere with subsequent DNA analysis of the fingerprints.
The fine spray prevents splashes that could damage prints, is less messy than a powder and works quickly even on rough surfaces where it is harder to capture fingerprints, such as brick.
“This system is safer, more sustainable and works faster than existing technologies and can even be used on fingerprints that are a week old," said Tony James, from the Department of Chemistry at the University of Bath. “Having two different colors available means the spray can be used on different colored surfaces. We’re hoping to produce more colors in the future.”
“The probes are only weakly fluorescent in aqueous solution, but emit strong fluorescence once they bind to the fingerprints through the interaction between the probes and fatty acids or amino acids," said Luling Wu, also from the University of Bath.
The team is already collaborating with companies to make the dyes available for sale. Meanwhile, further work is ongoing.
A study is published in the Journal of the American Chemical Society.
Republished courtesy of University of Bath