One bacterium’s sound
Farbod Alijani’s Delft University of Technology team (TU Delft), was initially investigating the basic mechanics of graphene when a strange idea struck them. They were curious to see what would happen if graphene, an extremely sensitive material, came in contact with one biological object. Alijani says graphene, a type of carbon that is composed of a single layer atoms, is known as the “wonder material”. It is strong and has excellent electrical and mechanical properties. It’s also very sensitive to external forces.
Farbod Alijani’s research team initiated a collaboration between the Cees Dekker nanobiology group and Peter Steeneken nanomechanics groups. The scientists conducted their first experiments with E. coli together with Irek Roslon, PhD student and Dr. Aleksandre Japadze, postdoc. E.coli bacteria. Cees Dekker: What we saw was remarkable! A single bacterium can adhere to the graphene drum’s surface, generating random oscillations at amplitudes below what we could detect. The sound of one bacterium could be heard!
A bacterium is used to punch a graphene drum
These oscillations result from the biological processes of bacteria. The main contribution comes from their flagella, which are the tails on the cell surface that propel bacteria. It’s important to note that these graphene flagellar beats are 10 billion times smaller than the punch of a boxer when he hits a punch bag. Alijani says that these nanoscale beats can still be converted into sound tracks and listened too.
Graphene is fast to detect antibiotic resistance
This research is crucial for the detection and treatment of antibiotic resistance. The experimental results were unambiguous: If bacteria was resistant to antibiotics, oscillations continued at the same level. The vibrations dropped to a minimum of one or two hours after the antibiotic was administered, but then disappeared completely. The phenomenon can be detected in just one cell due to its high sensitivity with graphene drums.
Farbod Alijani says: “For future, we aim to optimize our single-cell graphene antibacterial sensitivity platform and validate against a variety pathogenic samples. It will eventually be used as a diagnostic toolkit to quickly detect antibiotic resistance in clinical practice.” Peter Steeneken concluded: “This would prove invaluable in the fight against antibiotic resistant, which is an ever-increasing menace to human health all over the globe.”