Graphene is an engineer’s wonder material. Graphene is a unique nanomaterial with exceptional flexibility and strength. Almost transparent in thin layers, graphene is about 100 times stronger than the strongest steel. Its ability to conduct electricity makes graphene an excellent material for biomedical applications. Graphene is a sheet of carbon that is just one atom thick; it is difficult to produce in large quantities. We’ve written about many applications for graphene, including a graphene sensor that detects lung inflammation, low-cost graphene antennas, and printed, stretchable nanowires. Without financially feasible graphene production methods, however, researchers find it difficult to move the technology out of the labs and into commercial applications.
Researchers at the Delft University of Technology and the University of Rochester have discovered a way to produce graphene on a large scale using microbial reduction with a specific bacteria, Shewanella oneidensis. The researchers converted common graphite to graphene in two stages using a process published in ChemOpen. Graphite is extracted from rocks from underground and open-pit mines. The team starts by exfoliating graphite with a strong oxidizer to produce graphene oxide; sulfur dioxide is a byproduct. The graphene oxide is mixed with the bacteria and left to sit. In a short time — overnight in experiments at the University of Rochester — the bacteria consumes the oxygen, leaving a form of highly conductive graphene.
According to Rochester associate professor of biology Anne S. Meyer, the process she and colleagues at Delft derived has potential applications in computer technology and medical equipment such as field-effect transistor (FET) biosensors and conductive ink. The international team also developed a way to create graphene material that is conductive on only one side, which Meyer terms “bacterial lithography.”
