Abstract. Polyaniline (PANI) is the most important conducting polymer with excellent electrochemical properties. So PANIbased biosensors may find wide applications in medical diagnostics. We report here a ternary nanocomposite of gold nanoparticle-decorated single-walled carbon nanotubes (SWCNTs) embedded in sulfonated polyaniline matrix, prepared using a simple solvothermal chemical route. The structural and morphological characteristics have been determined by electron microscopy, X-ray diffraction and Raman spectroscopy. Optical characteristics of the nanocomposite have been determined by ultraviolet (UV)-visible absorption spectroscopy and photoluminescence spectroscopy. The direct current (DC)-conductivity measurement of the material shows a significant increase in electrical conductivity at 353 K from 7.80·10 -2 S/m for pure SPANI to 10.91 S/m for the 3-phase nanocomposite as synthesized in the present investigations. Thus the incorporation of SWCNT/Au nanohybrid fibers in the PANI matrix enhanced its electrical properties. Sulfonation increased the processability of the material, as the samples have now been found to be soluble in water and common organic solvents like DMSO. Such a functional nanocomposite will make an excellent biosensor electrode material.