Glassy carbon electrode (GCE) has been modified by mechanical entrapment method with Polyaniline Nanoparticles / Graphene for developing a new nanosensor (PANINPs/GR/GCE). It was characterized by electrochemical analysis to evaluate it as a nano-sensor for analytical electrochemistry. A standard solution of 0.06 mM K₄[Fe(CN)₆] in 0.1M KCl was used as an electrolyte, in order to study the Fe(II) / Fe(III) redox current peaks at various concentrations, pH, scan rates, measurement of diffusion coefficient, stability and reliability on the modified electrode. It was found that the new modified electrode (PANINPs/GR/GCE) improved the oxidation-reduction current peaks of Fe(II)/Fe(III) ions at 25 ^oC from 6.71 to 23 µA and -5.14 to -17.5 µA, respectively. The current ratio anodic to cathodic current peaks was found Ipa/Ipc ≈ 1 of the new modified electrode with the potential peak separation of ∆E_pa-c = 100 mV, which has shown a reversible and heterogeneous reaction of the new modified electrode in electrolyte. The new nanosensor has low detection limit, with good reliability and stability of nanoparticles on the GCE surface, and improved the oxidation-reduction current peaks in acidic medium.