Contaminated fingerprints leave dark shadows on the films, which glow blue under ultraviolet light. One of the films can distinguish between different classes of explosive chemicals, a property that could provide evidence to help solve a crime, or prevent one.
A recent episode of CSI: Miami featured the technology, which linked fingerprints left on a video camera to a bomb used in a bank heist, revealing the motive for the robbery. In real life, the security systems company RedXDefense has developed a portable kit based on the technology that security officers could use with minimal training.
Detection relies on fluorescent polymers developed at UCSD by chemistry and biochemistry professor William Trogler and graduate student Jason Sanchez. “It’s a very intuitive detection method that doesn’t require a scientist to run,” Trogler said.
Sanchez and Trogler describe the synthesis and properties of their polymers in a forthcoming issue of the Journal of Materials Chemistry.
The polymers emit blue light when excited by ultraviolet radiation. Nitrogen-based explosive chemicals such as TNT quench that glow by soaking up electrons.
Because the polymers fluoresce brightly, no special instruments are needed to read the results. Only a very thin film sprayed on a suspect surface is needed to reveal the presence of a dangerous chemical. A single layer of the polymer, about one thousandth of a gram, is enough to detect minute amounts of some explosives, as little as a few trillionths of a gram (picograms) on a surface a half-foot in diameter. Handling explosives can leave 1,000 times that quantity or more stuck to fingers or vehicles.
The films also adhere directly to potentially contaminated surfaces, making them more sensitive than previous methods, which rely on capturing molecules that escape into the air.
Detection can be fast, revealing incriminating fingerprints as soon as the solvents dry, within 30 seconds. Exposure to ultraviolet light for an minute or two alters one of the films so that traces a nitrate esters, a class chemicals that includes the highly explosive PTEN, begin to glow green. Traces of other classes of explosives, such as nitroaromatics like TNT, stay dark.
Trogler’s group is currently developing similar systems to detect explosives based on peroxides.
The Air Force Office of Scientific Research and RedXDefense funded the research. Sanchez was supported by the National Science Foundation.
Trogler serves on the strategic advisory board of RedXDefense, which has licensed the technology from UCSD.
Comment: William Trogler (858) 534-6175, email@example.com
Susan Brown | newswise
Turning carbon dioxide into liquid fuel
06.08.2020 | DOE/Argonne National Laboratory
Tellurium makes the difference
06.08.2020 | Friedrich-Schiller-Universität Jena
Scientists at the Fraunhofer Institute for Laser Technology ILT have come up with a striking new addition to contact stamping technologies in the ERDF research project ScanCut. In collaboration with industry partners from North Rhine-Westphalia, the Aachen-based team of researchers developed a hybrid manufacturing process for the laser cutting of thin-walled metal strips. This new process makes it possible to fabricate even the tiniest details of contact parts in an eco-friendly, high-precision and efficient manner.
Plug connectors are tiny and, at first glance, unremarkable – yet modern vehicles would be unable to function without them. Several thousand plug connectors...
An international research team has found a new approach that may be able to reduce bone loss in osteoporosis and maintain bone health.
Osteoporosis is the most common age-related bone disease which affects hundreds of millions of individuals worldwide. It is estimated that one in three women...
Traditional single-cell sequencing methods help to reveal insights about cellular differences and functions - but they do this with static snapshots only...
“Core-shell” clusters pave the way for new efficient nanomaterials that make catalysts, magnetic and laser sensors or measuring devices for detecting electromagnetic radiation more efficient.
Whether in innovative high-tech materials, more powerful computer chips, pharmaceuticals or in the field of renewable energies, nanoparticles – smallest...
An international research team with Prof. Cornelia Denz from the Institute of Applied Physics at the University of Münster develop for the first time light fields using caustics that do not change during propagation. With the new method, the physicists cleverly exploit light structures that can be seen in rainbows or when light is transmitted through drinking glasses.
Modern applications as high resolution microsopy or micro- or nanoscale material processing require customized laser beams that do not change during...
23.07.2020 | Event News
21.07.2020 | Event News
07.07.2020 | Event News
06.08.2020 | Earth Sciences
06.08.2020 | Power and Electrical Engineering
06.08.2020 | Life Sciences