Infrared (IR) spectroscopy provides fingerprinting of the energy and orientation of molecular bonds. The IR signals are generally weak and require amplification. Here we present a new plasmonic platform, made of freely suspended graphene, which was coating periodic metal structures. Only monolayer thick films were needed for a fast signal recording. We demonstrated unique IR absorption signals of bound proteins: these were the hemagglutinin area (HA1) of swine influenza (Hi NI) and the avian influenza (H5N1) viruses bound to their respective tri-saccharides ligand receptors. The simplicity and sensitivity of such approach may find applications in fast monitoring of binding events. (C) 2013 Elsevier B.V. All rights reserved.