The investigation of the effects of synthesis parameters on the microstructure an‎d the physical an‎d chemical properties of magnetic/antibacterial nanoparticles based on iron coated with mesoporous silica containing silver nanoparticles

10/22/2026 12:00:00 AM

In recent years, multifunctional nanoparticles with magnetic an‎d antibacterial properties have attracted widespread attention in biomedical an‎d medical applications due to their unique characteristics, including small size, high specific surface area, an‎d tunable physicochemical properties. In the present study, a magnetic/antibacterial nanocomposite based on zero-valent iron coated with mesoporous silica an‎d decorated with silver nanoparticles was synthesized an‎d characterized.Various analytical techniques were employed to investigate the structure an‎d properties of the synthesized samples: X-ray diffraction (XRD) was used to determine the crystalline phases; Fourier-transform infrared spectroscopy (FTIR) identified the functional groups of silica; field-emission scanning electron microscopy (FE-SEM) provided insights into the morphology an‎d particle size; nitrogen adsorption–desorption analysis (BET) measured the specific surface area an‎d porosity; a vibrating sample magnetometer (VSM) eva‎luated the magnetic properties; an‎d magnetic hyperthermia tests assessed the heat generation ability of the nanoparticles under an alternating magnetic field. Additionally, the biological effects of the nanocomposite were examined using an MTT cytotoxicity assay on the human breast cancer cell line (MDA-MB-231). The XRD pattern confirmed the presence of the zero-valent iron phase (without noticeable oxidation) along with diffraction peaks corresponding to silver nanoparticles, while the FTIR spectrum revealed Si–O–Si bond vibrations in the silica shell, indicating successful silica coating on the iron nanoparticles. Microscopic images showed that silver nanoparticles were uniformly distributed over the silica shell surface, an‎d the average particle size of the nanocomposite remained within the nanometer range. BET surface analysis demonstrated that the Fe⁰@SiO₂@Ag nanocomposite possessed a high specific surface area (~700 m²/g), only slightly lower than that of pure mesoporous silica (~828 m²/g). Magnetic property eva‎luation showed that the saturation magnetization (Ms) of zero-valent iron decreased from approximately 93 to 30 emu/g after silica coating an‎d silver decoration. The magnetic hyperthermia test revealed the nanocomposite’s excellent heating performance under an alternating magnetic field, confirming its potential for localized thermal therapy applications. Furthermore, the MTT assay indicated notable anticancer activity of the nanocomposite: at higher concentrations (e.g., 500 μg/mL), more than 90% of cancer cells were destroyed within 24 hours, an‎d prolonged incubation up to 72 hours enhanced cytotoxicity even at lower concentrations.

نانو كامپوزيت هاي هسته-پوسته – آهن صفر ظرفيتي- پوشش مزومتخلخل سيليكا – نانو ذرات نقره

Core–shell nanocomposites; Zero-valent iron; Mesoporous silica coating; Silver nanoparticles; Magnetic hyperthermia; Antibacterial activity.

soheil farshidmonfard

maryam tajabadi- mohammadreza aboutalebi