Big and expensive machines are currently used to detect cancer, requiring patients to visit health facilities to get checked, but this could change in the future.

Chemical engineers from the University of Michigan have developed a thin, flexible film that may eventually lead to the development of smaller and cheaper cancer detection technologies.

The film can produce circularly polarized light that coils into a three-dimensional helix shape, an ability considered crucial to cancer detection processes that can detect biomarkers of cancer in the blood. It uses layers of reflective gold nanoparticles to induce reflectivity.

"We used gold nanoparticles for two reasons," said Yoonseob Kim from the university. "They're very good at polarizing the kind of visible light that we were working with in this experiment. In addition, they're very good at self-organizing into the S-shaped chains that we needed to induce circular polarization."

Researchers hope the film can pave way for building phone-sized cancer detection devices that patients can use in the comfort of their home.

Engineering professor Nicholas Kotov said such a device could be very helpful as more frequent monitoring would allow doctors to catch the recurrence of cancer earlier and more effectively track the effectiveness of medications they prescribe. It could also give patients better peace of mind.

The detection process works by identifying proteins and DNA in the blood that indicate the presence of cancer. Synthetic biological particles designed to attract these biomarkers are coated with a reflective layer that reacts to circularly polarized light.

The particles are then added to a patient's blood sample. Under circularly polarized light, the particles can be seen binding to the biomarkers. A detection device is likewise used to determine whether or not the particles bind with the cancer biomarkers.

Kotov said the easy to manufacture film creates many potential applications for circularly polarized light, and detecting the presence of cancer is just one of them.

"Chiroptical effects at the nexus of mechanics, excitonics and plasmonics open new operational principles for optical and optoelectronic devices from nanoparticles, carbon nanotubes and other nanoscale components," Kotov and colleagues wrote in their study, which was published in Nature Materials on Jan. 4.