Thermodynamic properties of quasiparticles in a graphene-based structures are investigated. Two graphene superconducting layers (one superconducting component is placed on the top layered-graphene structure and the other component in the bottom) separated by oxide dielectric layers and one normal graphene layer in the middle. The quasiparticle flow emerged due to external gate voltage, we considered it as a gas of electron-hole pairs whose components belong to different layers. This is a striking result in view of the complexity of these systems: we have established that specific heat exhibits universal (- T3) behavior at low T, independent from the gate voltage and the superconducting gap. The experimental observation of this theoretical prediction would be an important step towards our understanding of critical massless matter.