Four Northwestern graduate students have created a new chip-sized sensor that will make it easier to detect dangerous substances in patients.

The sensor, 3mm in length, uses a laser and an antenna to identify and catalogue low-concentration biomolecules, such as cancer antigens or anthrax spores. This technology is especially useful in the detection of bacteria, viruses, proteins and biomolecules that are difficult to extract from biological systems, said Ryan Gelfand, one of the students who worked on the project.

“The sensor is initially a first step toward a … ‘lab on a chip,'” said Gelfand. “So the idea is that you’re in an ambulance or you’re at the doctor’s office, and they can check for cancer antigens to see if you have cancer right at the point of care.”

That way, the patient wouldn’t have to wait several days for blood work results.

Under the supervisionof Associate Professor Hooman Mohseni in the Bio-inspired Sensors and Optoelectronics Laboratory, Gelfand acted as a molecular biology and physics expert. Gelfand worked with fellow EECS students Jack Kohoutek, who focused on optical measurement; Dibyendu Dey, the lasers and fabrication specialist; and Alireza Bonakdar, who aided in the theoretical component of the project.

While detecting biomolecules – organic molecules commonly known as pharmaceuticals – is fairly easy, the problem lies in detecting molecules in low concentration, he said.

“The real challenge is quantity,” Gelfand said. “For example, one anthrax spore could create a whole epidemic. It’s the needle in a haystack problem. If I give you an entire box of baking soda, and I hid in that little box of baking soda one spore of anthrax, we cannot detect it with the technologies that we have now, but it certainly can still be dangerous.”

While the medical market stands as the primary beneficiary of this sensor, there are other potential applications for its use, such as homeland security, Gelfand said. For example, he said the chip could make it easier to determine whether powder on an envelope is anthrax.

In the larger scheme and commercialization of the device, the team hopes that the sensor becomes a small, low-power, very sensitive technology capable of monitoring the important chemicals in the body via cell phone, Mohseni said.

“The goal is that all cell phones could monitor and send directly to a secure computer chemical levels, and the doctor would receive an alert if something goes out of the norm,” Mohseni said. “But, also outside of acute events, this sensor could be used to detect gradual change in your baseline chemistry in the body … like a constant wireless health care system.”

[email protected], contributing writer