Multilayered electromagnetic bionanocomposite based on alginic acid: Characterization and biological activities

•Multilayered bionanocomposite based on alginic acid was synthesized by two methods.•Determination of the super-paramagnetic property for the bionanocomposite.•Good antimicrobial activities for the synthesized bionanocomposite.•Improvement of the thermal stability of the bionanocomposite.•Confirming the nanosphere structure of the bionanocomposite by SEM images. Poly(aniline-co-pyrrole)@Fe3O4@alginic acid (PACP@Fe3O4@AA) bionanocomposite was synthesized by a two-step method. In the first step, the AA@Fe3O4 nanocomposite was synthesized via the in-situ co-precipitation technique. In the second step, the PACP@Fe3O4@AA bionanocomposite was synthesized through the emulsion polymerization. Several techniques such as Fourier transform infrared spectroscopy, X-ray diffraction, ultraviolet visible spectroscopy, scanning electron microscopy, and thermogravimetric analysis were utilized for the characterization of the synthesized materials. The presence of AA@Fe3O4 in the bionanocomposite enhanced the electrical conductivity as well as the thermal stability of the PACP@Fe3O4@AA bionanocomposite. The scanning electron micrograph of the PACP@Fe3O4@AA bionanocomposite demonstrated a nanosphere structure. The vibrating sample magnetometer analysis displayed that both AA@Fe3O4 and PACP@Fe3O4@AA bionanocomposites were super-paramagnetic at room temperature. The PACP@Fe3O4@AA bionanocomposite had good antioxidant and antibacterial activities. Furthermore, a synergistic effect was observed for the antifungal activity.