Bacteria-filled liquid crystals could improve disease detection

By placing living, swimming bacteria in a novel water-based, nontoxic liquid crystal, researchers created a living liquid crystal that may improve disease detection, according to a recent scientific presentation.

Researchers at Ohio's Kent State University and Illinois' Argonne National Laboratory created the new form of soft matter, which moves and reshapes itself in response to external stimuli. The research team presented its findings this week during the 58th annual Biophysical Society Meeting in San Francisco.

Using a simple polarizing microscope, researchers were able to see with unusual clarity the wake-like trail stimulated by the rotation of bacterial flagella. Bacterial flagella are approximately 24 nanometers thick, which is equivalent 1/4000th the thickness of a typical human hair.

Most importantly for disease detection, researchers were able to guide and control active movements of the bacteria by manipulating temperature, surface alignment or oxygen availability. Living liquid crystal may provide a medium to amplify microscopic reactions occurring at the nano- and micro-scales, where viruses and molecules interact. Living liquid crystal may be able to make sensing devices that monitor infection and cancer growth.

"As far as we know, these things have never been done systematically as we did before in experimental physics," Shuang Zhou, one of the researchers, said. "There are many potential applications for this kind of new material, but some of the more immediate are new approaches to biomedical sensing design. (The investigation is like the) first handful of gold scooped out of a just-opened treasure chest. There are many more things to be done."