Nickel oxide (NIO) nanoparticles synthesized via hydrothermal method are reported and it is used for modification of carbon paste electrode (MCPE). The structural characterization of nanopowder by XRD clearly shows the formation of face-centered cubic (FCC) crystalline structure with high crystallinity. The morphological structure is characterized by field emission scanning electron microscope shows the formation of flake like structures. The modified electrode is used for the determination of dopamine, Folic acid (FA) and paracetamol separately using cyclic voltammetry. The voltammograms obtained during the oxidation studies revealed that nano NiO exhibits better catalytic function towards the oxidation of Dopamine (DA) and paracetamol (PC). The overlapping voltammetric response of both the biomolecules at the bare electrode gets resolved into well-defined voltammetric peaks with enhanced oxidation currents in 1×10-5M DA in 0.2 M PBS pH 7.4.