Credit: ACS publications
In a recent study in the scientific world, by interfacing brain cells onto graphene, researchers have shown that they can differentiate a single hyperactive cancerous cell from a normal cell, pointing the way to developing a simple, noninvasive tool for early cancer diagnosis. "This graphene system is able to detect the level of activity of an interfaced cell," says the scientist who led the research.
Graphene is the thinnest known material and is very sensitive to whatever happens on its surface. The nanomaterial is composed of a single layer of carbon atoms linked in a hexagonal chicken-wire pattern, and all the atoms share a cloud of electrons moving freely about the surface. The cell's interface with graphene rearranges the charge distribution in graphene, which modifies the energy of atomic vibration as detected by Raman spectroscopy.
The atomic vibration energy in graphene's crystal lattice differs depending on whether it's in contact with a cancer cell or a normal cell, because the cancer cell's hyperactivity leads to a higher negative charge on its surface and the release of more protons.
The electric field around the cell pushes away electrons in graphene's electron cloud , which changes the vibration energy of the carbon atoms. The change in vibration energy can be pinpointed by Raman mapping with a resolution of 300 nanometers, he said, allowing characterization of the activity of a single cell.
The electric field around the cell pushes away electrons in graphene's electron cloud, which changes the vibration energy of the carbon atoms. The change in vibration energy can be pinpointed by Raman mapping with a resolution of 300 nm, allowing characterization of the activity of a single cell.
The study looked at cultured human brain cells, comparing normal astrocytes to their cancerous counterpart, the highly malignant brain tumor glioblastoma multiforme. The technique is now being studied in a mouse model of cancer, with results that are very promising. Experiments with patient biopsies would be further down the road, says the researcher.
Once a patient has brain tumor surgery, this technique could be used to see if the tumor relapses. For this purpose, a cell sample could be interfaced with graphene to see if cancer cells are present. The same technique may be put to use to distinguish between Gram- positive or Gram- negative bacteria, and also to detect sickle cells.
Earlier this year, this same group of researchers introduced nanoscale ripples in graphene, causing it to conduct differently in perpendicular directions, useful for electronics. They wrinkled the graphene by draping it over a string of rod-shaped bacteria, then vacuum-shrinking the germs. They took this previous work and flipped it over, wherein they laid cell son graphene and studied graphene’s atomic vibrations.