Aniline was copolymerized chemically in presence of five different concentrations of 4,4'-diaminodiphenyl sulphone using potassium persulphate. The copolymer exhibited good solubility in DMF and DMSO. Copolymers were characterized by UV-VIS, FTIR, XRD and SEM studies. The formation of polymer through N-H group was understood from the single N-H stretching vibrational frequency at 3378 cm(-1) and bands at 1630 and 1494 cm-1 for quinonoid and benzenoid structures, respectively. The stretching vibration of sulphone S = O at 1115 cm(-1) clearly indicated the presence of DDS in the copolymer. The X-ray diffraction studies revealed the formation of nano sized crystalline copolymer. When more DDS was incorporated in the copolymer the crystalline nature changed from less to more. The grain size of the copolymer calculated from Scherrer's formula was 83 nm. The nano size copolymer formation was also confirmed through surface morphology (100 nm) studies. The electrical property of the copolymer was studied by four-probe conductivity meter. The synthesized polymers have conductivity of 7.21 x 10(-3) to 2.07 x 10(-3) S cm(-1). The voltammetric and spectroelectrochemical results were also presented. (c) 2006 Elsevier Ltd. All rights reserved.