We present the successful integration of graphene on top of AlN-based solidly mounted resonators (SMRs), using a low temperature CVD process and Ni layers as catalyst. We develop a protocol to functionalize the surface of the resonators that starts with a low damage O2 radical plasma treatment of the surface of the devices that introduces a controlled density of defects on the graphene. Then, EDC/NHS chemistry is used to covalently bond streptavidin molecules to the surface of the sensors. Finally, the functionalised biosensors are assessed by analysing their response to biotinylated antibodies.