A team of scientists brought together through UCSB’s Institute for Collaborative Biotechnologies recently engineered a device that biomimics a dog’s scent receptors in order to identify various molecules.
The basic technology that the device relies on combines principles of chemistry and engineering to concentrate and accurately describe molecules, potentially serving to detect explosives or test for a variety of pathogens. Led by chemistry professor Martin Moskovits and mechanical engineering professor Carl Meinhart, the product was completed by former doctoral researchers Brian Piorek of mechanical engineering and Seung Joon Lee of the chemistry department.
According to Professor Moskovits, the device is superior in specificity when compared to the older, more unreliable detectors due to its identification technique.
“We identify a molecule by some sort of fingerprint, which in the molecular world, is a molecule’s vibrational spectrum. Our device has always been based on recording the entire spectrum of a molecule and going into a computer’s memory, fishing out a whole bunch of fingerprints and iden- tifying the exact match,” Moskovits said. “This way, we get far fewer … false alarms. That’s one of the things we are particularly proud about this device, it gives you a spectrum that is a fingerprint of your target substance.”
The device is comprised of a free-surface microf luidic channel — a small partially open canal of fluid that continuously incorporates vapor molecules into the liquid inside — connected to a small computing device. Nanoparticles on the inside of the channel bind to molecules incorporated into the liquid as a laser amplifies the unique “spectral signature” of each molecule. A computer chip connected to the device then sorts through a database of these spectral signatures to identify a match.
Meinhart and Moskovits first began discussion of this particular system while attending ICB meetings. During a conversation about microfluidics, Moskovits brought up his idea of a microfluidic channel with an open top, exposing the usually covered liquid to the atmosphere. While this innovation enabled Moskovits to capture and quickly concentrate a large amount of molecules, it was through collaboration that he and Meinhart could eventually engineer the final identification system.
In the publication of their results in the scientific journal Analytic Chemistry, the team focused on the sensor’s ability to detect explosives — a task usually given to “sniffer dogs,” which can identify trace amounts of chemicals. The device was shown to accurately detect 2,4-Dinitrotoluene, a vapor emitted by TNT-based explosives. As the ICB is partly funded by the U.S. Army, Meinhart noted that this ability to accurately detect explosives was a main goal on the team’s agenda.
According to Meinhart, the mechanics behind this device were not originally directly modeled after a dog’s nose, but the power of this analogy and application grew as he and his team refined the sensor.
“Molecules of explosives will be difficult to recognize, so you need to concentrate them so that the detector gets more than the initial share,” Meinhart “As we worked, we realized we were seeking the same kind of operations that function in a dog’s nose. The dog evolved these things after many years of evolution, so it is likely that when we seek to mimic what a dog does, certain operational details would be in parallel.”
SpectraFluidics, the Santa Barbara- based company that Piorek co-founded in 2008 and currently serves as Chief Scientist for, obtained the exclusive license for the device.
Meinhart and Moskovits plan to unveil a wide range of new discoveries over the next few years involving collaboration efforts between many departments within the ICB. These new developments include being able to identify methamphetamine on a person’s breath and the development of a blood test capable of detecting small amounts of cancer cells in order to more quickly diagnose and treat patients.
Both Moskovits and Meinhart credit UCSB’s relaxing atmosphere and unique emphasis on interdisciplinary collaboration as the key to the university’s dynamic scientific advances.
“I’ve worked at four-year universities, and I’ve visited 100, maybe more, and there is no place like UC Santa Barbara in terms of interdisciplinary collaboration. It’s something that so many universities try to do, and very few come close. That story at UCSB is the secret sauce as to why UCSB has gone from being the sleepy little party school on the beach to this behemoth in science and engineering — still on the beach, by the way,” Moskovits said.
A version of this article appeared on page 5 of January 23rd, 2013’s print edition of the Nexus.