[en] Highlights: •Multilayered graphene decorated with Pt nanoparticles used in GFET nanobiosensors •Reduced graphene oxide flakes functionalized with carbon disulfide for biosensing •Study of Platinum dithiocarbamate complexes on graphene flakes by XPS and voltammetry -- Abstract: Multilayered reduced graphene oxide decorated homogenously with Platinum nanoparticles (rGO/Pt) was confirmed by Transmission Electron Microscopy and X-ray diffraction. It was found that the rGO/Pt flakes were suitable for adsorbing biomolecules in one step with the use of carbon disulfide (CS₂) based compound. In this context, the adsorption-interaction of CS₂ and Human Serum Albumin biomolecules on rGO/Pt (forming Platinum dithiocarbamate complexes) was confirmed by X-ray photoelectron spectroscopy and cyclic voltammetry techniques in neutral conditions. As a proof of concept, this nanocomposite was used as a transducer in Back-gated Field Effect Transistor (GFET) based nanobiosensors. The fabrication of GFET devices, at the level of 2-inch wafer, was conducted by conventional photolithography. The CS₂, rGO/Pt and protein G that detects IgG, were locally deposited by using a commercial microplotter instrument. The experiments demonstrated that the homogenous decoration with Platinum nanoparticles as surface could permit the detection of biomolecules by using non-uniform graphene flakes functionalized with CS₂, for rapid elaboration of electrochemical and electrical-nanobiosensors.