Scientists have developed a forensic spray that uses a protein found in jellyfish to detect fingerprints in just 10 seconds.
They argue that dye sprays could make forensic investigations faster and more effective. It is also water soluble and has low toxicity. Traditional forensic methods use toxic powders that can damage DNA evidence, or petrochemical solvents that harm the environment, and their sale is becoming increasingly restricted.
The dye in the spray is based on a fluorescent compound called green fluorescent protein (GFP), which has previously revolutionized scientists' ability to visualize biological processes in cells and animals. The dye is biologically compatible and does not interfere with subsequent DNA analysis of the fingerprint.
“This system is safer, more sustainable, faster than existing technologies, and can even be used for week-old fingerprints,” said Professor Tony James, a chemist at the University of Bath and co-author of the study. said.
The research team created two different colored dyes called LFP-yellow and LFP-red that bind to chemicals found in sweat and skin oils. This locks the dye molecules in place and produces a fluorescent emission that can be seen under blue light.
“Having two different colors means the spray can be used on different colored surfaces. We hope to create even more colors in the future,” James said. .
The fine spray prevents splashes that can damage prints, leaves less mess than powder, and works quickly on rough surfaces where prints are difficult to capture, such as brick.
When the suspect is unknown, fingerprints continue to identify people more often than DNA evidence, and the technology is faster and cheaper than DNA profiling. However, governments are increasingly restricting the use of solvents used in fingerprint detection methods, such as per- and polyfluoroalkyl substances (PFAS), also known as “forever chemicals.”
GFP protein is naturally produced in North American jellyfish Aequore jellyfish, also called crystal jellyfish, emits a green glow when it absorbs blue light. Scientists don't know what purpose fluorescence serves for jellyfish, but one possibility is that it helps scare away predators.
The protein is already widely used in biological research because the GFP gene can be used as a harmless glow-in-the-dark tag to track the activity of cells in laboratory dishes and within living organisms. Flatworms, tadpoles, and zebrafish have all been reprogrammed with the GFP gene.
“We hope that this technology can really improve evidence detection at crime scenes,” said the project's lead researcher, Professor Chusen Huang of Shanghai Normal University in China.
The research team is collaborating with companies and aims to commercialize the forensic dye. Their research is published in the Journal of the American Chemical Society.
