Substrates Affect Grapheneâ€™s Chemical ReactivenessCategory: Science & Technology
Posted: August 22, 2012 09:34AM
Graphene is an atom-thick sheet of carbon with a hexagonal pattern to it that has many amazing properties. These include great strength, flexibility, and conductivity and all contribute to researchers' interest in using the material. Sometimes however the properties of a sample of graphene are different from what one would expect, which has confused researchers in the past. Now those at MIT have found a solution for why and it could open up many new possibilities for the material.
Being an atom thick, graphene is the thinnest material known to man and it turns out this characteristic is more impressive than many thought. When on top of another material, like silicon dioxide, the electrical fields of the substrate's molecules actually reach through the graphene, and impact how it reacts to other molecules. If the substrate is silicon dioxide, graphene is reactive to certain chemicals, but if the substrate is boron nitride, there are barely any reactions with the same chemicals. As the substrate is completely covered by the layer of graphene however, only the graphene interacts with the chemical.
This could ability to control the local reactivity of graphene opens up many doors for biological sensors. Certain regions of the graphene devices would interact with the biological molecule, but do so in a way that does not damage the molecule, which is not always possible with modern sensing techniques.