A nanocomposite material (purple) conducts electrons released by exoelectrogenic bacteria (green) to ... [+]
A new gel made of carbon nanotubes and nanoparticles of silica woven together with strands of DNA has allowed researchers to tap into the power of certain electricity-producing bacteria.
Exoelectrogenic bacteria like Shewanella oneidensis produce electricity naturally and scientists have long worked on methods to harness this natural power source. Doing so presents a number of unique challenges when developing a conductive material that is also conducive to bacterial growth, efficient and easily programmable so as to control the current.
The answer for a team of researchers from Germany’s Karlsruhe Institute of Technology was to combine some high-tech nanomaterials into a liquid gel form held together by strands of DNA on which the bacteria can grow, thrive and pump out electrons in the process.
“The Shewanella-containing composite remains stable for several days and shows electrochemical activity,” the scientists write in Applied Materials and Interfaces.
Even better for the power potential of the bacteria is the fact that the nano-gel host was able to collect the electrons and conduct them to an anode, essentially creating a living battery.
The work builds off plenty of previous research on bacteria with real power potential.
The researchers report that their new material enables them to create a system that not only harvests and conducts electricity, but it also a “programmable biohybrid.” Adding an enzyme that cuts the DNA strands effectively breaks down the material, acting as a sort of “off switch” for the flow of electrons.
The team says their biohybrid system could be used not just as a power source, but to make other sorts of components as well.
“We believe that the application possibilities of such biohybrid materials could even go beyond microbial biosensors, bioreactors, and fuel cell systems,” they write.
