
356 Biosensors Based on Nanomaterials and Nanodevices
One route for non-destructive functionalization of graphene is π–π interfacing
(Figure 14.4). Here, π–π bonded molecules on graphene do not disturb the sp
2
hybridization
state of the carbon atoms on graphene such that the high mobility of graphene is retained.
Here, the π electrons on graphene enable π–π interfacing with π–activated polyaromatic
molecules like anthracene, pyrelene, pyrene, coronene, etc. Polycyclic aromatic compounds
can bond with one another via π–orbital overlapping to form π –π bond, which is stronger
than hydrogen bond, van der Waals, and dipole–dipole interactions (