MIT engineers have succeeded in creating "biofilms," which combine bacterial cells with nonliving materials, such as gold nanoparticles, that can conduct electricity or emit light.
The hope is that biofilm, that slippery, slimy material made of bacteria that forms substances like dental plaque, may someday create functioning circuits that could be used to manufacture photovoltaic solar panels or act as "biosensors" that could sense toxins.
A depiction of the engineered bacteria that has incorporated gold nanoparticles and quantum dots — the red and green balls.
The hybrid biofilms have the attributes of living cells, which reproduce and assemble into structure and react to their environment, and materials such as metal that can conduct electricity.
The research, lead by Timothy Lu, an assistant professor of electrical engineering and biological engineering, was published in the March 23 issue of the journal Nature Materials.
The researchers used E. coli bacteria for their initial experiments because the biofilms produced with it contain "curli fibers," protein chains that help material attach to surfaces. The curli fibers can be modified by adding peptides, which trap nonliving nanoparticles, such as gold or quantum dots, a semiconductor material the size of a nano particle that can be embedded into living cells. The result is a biofilm that reproduces and can conduct electricity.
"It's an interesting way of thinking about materials synthesis, which is very different from what people do now, which is usually a top-down approach," Lu said in MIT News.
Another advantage of using cells to construct circuitry is that they can communicate with other cells in the structure and reshape the composition of the biofilm based on the nonliving material involved.
"It's a really simple system but what happens over time is you get curli that's increasingly labeled by gold particles. It shows that indeed you can make cells that talk to each other and they can change the composition of the material over time," Lu told MIT News. "Ultimately, we hope to emulate how natural systems, like bone, form. No one tells bone what to do, but it generates a material in response to environmental signals."
Sign up for MIS Asia eNewsletters.