  Monolayer graphene was deposited on a Si wafer substrate decorated with SiO2
nanoparticles (NPs) and then exposed to aryl radicals that were generated in
situ from their diazonium precursors. Using micro-Raman mapping, the aryl
radicals were found to selectively react with the regions of graphene that
covered the NPs. The enhanced chemical reactivity was attributed to the
increased strain energy induced by the local mechanical deformation of the
graphene.
