The new technology also can distinguish between overlapping fingerprints left by different individuals - a difficult task for current optical forensic methods.
A team led by R. Graham Cooks, Purdue's Henry Bohn Hass Distinguished Professor of Analytical Chemistry, has created a tool that reads and provides an image of a fingerprint's chemical signature. The technology can be used to determine what a person recently handled.
"The classic example of a fingerprint is an ink imprint showing the unique swirls and loops used for identification, but fingerprints also leave behind a unique distribution of molecular compounds," Cooks said. "Some of the residues left behind are from naturally occurring compounds in the skin and some are from other surfaces or materials a person has touched."
The team's research will be detailed in a paper published in Friday's (Aug. 8) issue of Science.
Demian R. Ifa, a Purdue postdoctoral researcher and the paper's lead author, said the technology also can easily uncover fingerprints buried beneath others.
"Because the distribution of compounds found in each fingerprint can be unique, we also can use this technology to pull one fingerprint out from beneath layers of other fingerprints," Ifa said. "By looking for compounds we know to be present in a certain fingerprint, we can separate it from the others and obtain a crystal clear image of that fingerprint. The image could then be used with fingerprint recognition software to identify an individual."
Researchers examined fingerprints in situ or lifted them from different surfaces such as glass, metal and plastic using common clear plastic tape. They then analyzed them with a mass spectrometry technique developed in Cooks' lab.
Mass spectrometry works by first turning molecules into ions, or electrically charged versions of themselves, so their masses can be analyzed. Conventional mass spectrometry requires chemical separations, manipulations of samples and containment in a vacuum chamber for ionization and analysis. Cooks' technology performs the ionization step in the air or directly on surfaces outside of the mass spectrometer's vacuum chamber, making the process much faster and more portable, Ifa said.
The Purdue procedure performs the ionization step by spraying a stream of water in the presence of an electric field to create positively charged water droplets. Water molecules in the droplets contain an extra proton and are called ions. When the charged water droplets hit the surface of the sample being tested, they transfer their extra proton to molecules in the sample, turning them into ions. The ionized molecules are then vacuumed into the mass spectrometer to be measured and analyzed.
Researchers placed a section of tape containing a lifted fingerprint on a moving stage in front of the spectrometer. The spectrometer then sprayed small sections of the sample with the charged water droplets, obtaining data for each section and combining the data sets to create an analysis of the sample as a whole, Ifa said. Software was used to map the information and create an image of the fingerprint from the distribution and intensity of selected ions.
Additional co-authors of the paper are Nicholas E. Manicke and Allison L. Dill, graduate students in Purdue's chemistry department.
The research was performed within Purdue's Center for Analytical Instrumentation Development located at the Bindley Biosciences Center in Purdue's Discovery Park.
Cooks' device, called desorption electrospray ionization or DESI, has been commercialized by Indianapolis-based Prosolia Inc., and the research was funded by Office of Naval Research and Prosolia Inc.Writer: Elizabeth K. Gardner, (765) 494-2081, email@example.com
Elizabeth K. Gardner | EurekAlert!
Putting food-safety detection in the hands of consumers
15.11.2018 | Massachusetts Institute of Technology
Next stop Morocco: EU partners test innovative space robotics technologies in the Sahara desert
09.11.2018 | Deutsches Forschungszentrum für Künstliche Intelligenz GmbH, DFKI
Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.
Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
09.11.2018 | Event News
06.11.2018 | Event News
23.10.2018 | Event News
16.11.2018 | Health and Medicine
16.11.2018 | Life Sciences
16.11.2018 | Life Sciences