The role of functionalized nitrogen doped graphene (NGp) using poly(diallyldimethylammonium chloride) (PDDA) as modified electrode has been discussed. Pt-Pd bimetallic nanoparticles have been anchored on PDDA-NGp to form PtPd-PDDA-NGp nanocomposites, which are characterized by high resolution transmission electron microscope, X-ray diffraction and Raman spectroscopy. The simultaneous determination of paracetamol and tramadol has been carried out using the nitrogen doped graphene supported Pt-Pd nanoparticle modified glassy carbon electrode in 0.1 M Britton-Robinson buffer solution (pH 5.0). Two well-defined voltammetric peaks are obtained in square wave voltammogram measurements. It has been observed that the modified electrode can detect a wide linear range of concentrations of paracetamol from 5×10-6 to 1×10-4 M, and tramadol from 1.2×10-5 to 2.4×10-4 M. The limit of detection was found to be 1.8×10-7 and 5.7×10-6 M for paracetamol and tramadol, respectively (S/N = 3)
