  Controlled wrinkling of single-layer graphene (1-LG) at nanometer scale was
achieved by introducing monodisperse nanoparticles (NPs), with size comparable
to the strain coherence length, underneath the 1-LG. Typical fingerprint of the
delaminated fraction of 1-LG is identified as substantial contribution to the
principal Raman modes of the 1-LG. Correlation analysis of the Raman shift of
the modes clearly resolved the 1-LG in contact and delaminated from the
substrate, respectively. Intensity of Raman features of the delaminated 1-LG
increases linearly with the amount of the wrinkles, determined by advanced
processing of atomic force microscopy data. Our study thus offers universal
approach for both fine tuning and facile quantification of the graphene
topography up to ~ 60% of wrinkling.
