In this paper, two major projects have been successfully accomplished: Firstly, we introduced a novel and highly efficient route which was developed for the synthesis of Polyaniline (PANI) nanoparticles by using Potassium persulfate. Structure of nano PANI was characterized by FourierTransform Infrared (FT-IR), Proton Nuclear Magnetic Resonance (1H-NMR) and elemental analysis and the surface morphology of them was studied by scanning electron microscopy (SEM).Secondly, new nano-biosensors have been synthesized by using a simple and efficient method, from the reaction of nano PANI with the biocompatible branches, such as alaninemethyl ester and N-(4-aminobenzyl)-9H-purin-6-amine as a nucleobase and succinic anhydride as a spacer. The structures of 6 and 7 were confirmed by FT-IR and 1H-NMR. The interaction between alaninemethylester and nucleobase doped to nano PANI with short oligo phosphate chains of dsDNA (45 base pairs), was studied by fluorescence spectroscopy. The results showed that existence of dopants in the structure of nano PANI increases the interactions with DNA and this caused the decrease in the fluorescence emission intensity. تفاصيل المقالة