We
study the interplay of chemisorbed hydrogen and physisorbed
PbPc molecules on epitaxial graphene by means of surface transport
and density functional theory. While the adsorption of atomic hydrogen
induces strong localization by local sp3 rehybridization
of the graphene lattice, PbPc is not affecting the transport properties
of clean graphene. Moreover, on hydrogenated graphene, PbPc is selectively
lifting the lattice distortion, while binding the atomic hydrogen
and recovering the conductivity of the pristine graphene. Our results
show that graphene is a multipurpose template for sensing both chemisorbed
and physisorbed species and the implementation of a chemical selectivity.