The silver nanoparticles (AgNPs) have been embedded within the itaconic acid (IA), polyaniline (PANi), and copper oxide (CuO) to form Ag@PANi-IA-CuO polymeric nanocomposites. In-situ polymerization of itaconic acid has been carried out in the presence of aniline monomers using anhydrous iron trichloride as an oxidising agent. The piper betel leaf extract was used to a reduction of AgNO3. The anchoring of AgNPs onto nanocomposite has been characterized using different techniques such as Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED) X-ray diffraction (XRD), and energy-dispersive X-ray (EDX). Biological, magnetic, and thermal properties of nanocomposites have also been studied in antimicrobial, vibrating sample magnetometer (VSM), and thermogravimetric analysis (TGA). Hence, these types of silver nanoparticles anchored polyaniline-itaconic acid-CuO nanocomposite has shown an attractive application in the field of biomedical and wastewater treatment.