A novel nanomagnet modified with nickel ferrite nanoparticles (NPs) coated with hybrid chitosan (Cs–NiFe₂O₄) was synthesized using the co-precipitation method. The resulting nanomagnets were characterized using various techniques. The size of the nanomagnetic particles was estimated to be about 40 nm based on the transmission electron microscopy (TEM) image and X-ray diffraction analysis (XRD) pattern (using the Debye–Scherrer equation). Scanning electron microscopy (SEM) images indicated that the surface of Cs–NiFe₂O₄ NPs is flatter and smoother than the uncoated NiFe₂O₄ NPs. According to value stream mapping (VSM) analysis, the magnetization value of Cs–NiFe₂O₄ NPs (17.34 emu/g) was significantly lower than NiFe₂O₄ NPs (40.67 emu/g). The Cs–NiFe₂O₄ NPs indicated higher antibacterial properties than NiFe₂O₄ NPs and Cs. The minimum inhibitory concentrations of Cs–NiFe₂O₄ NPs against S. aureus and E. coli were 128 and 256 mg/mL, respectively. Antioxidant activity (evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging test) for NiFe₂O₄ NPs and Cs–NiFe₂O₄ NPs at the concentration of 100 µg/mL were 35% and 42%, respectively. Consequently, the synthesized Cs–NiFe₂O₄ NPs can be proposed as a viable material for biomedical applications.

Due to the characteristics of electrospun nanofibers (NFs), they are considered a suitable substrate for the adsorption and removal of heavy metals. Electrospun nanofibers are prepared based on optimized polycaprolactone (PCL, 12 wt%) and polyacrylic acid (PAA, 1 wt%) polymers loaded with graphene oxide nanoparticles (GO NPs, 1 wt%). The morphological, molecular interactions, crystallinity, thermal, hydrophobicity, and biocompatibility properties of NFs are characterized by spectroscopy (scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, Thermogravimetric analysis), contact angle, and MTT tests. Finally, the adsorption efficacy of NFs to remove lead (Pb²⁺) from water and apple juice samples was determined using inductively coupled plasma optical emission spectroscopy (ICP-OES). The average diameter for PCL, PCL/PAA, and PCL/PAA/GO NFs was 137, 500, and 216 nm, respectively. Additionally, the contact angle for PCL, PCL/PAA, and PCL/PAA/GO NFs was obtained at 74.32º, 91.98º, and 94.59º, respectively. The cytotoxicity test has shown non-toxicity for fabricated NFs against the HUVEC endothelial cell line by more than 80% survival during 72 h. Under optimum conditions including pH (= 6), temperature (25 °C), Pb concentration (25 to 50 mg/L), and time (15 to 30 min), the adsorption efficiency was generally between 80 and 97%. The adsorption isotherm model of PCL/PAA/GO NFs in the adsorption of lead metal follows the Langmuir model, and the reaction kinetics follow the pseudo-second-order. PCL/PA/GO NFs have shown adsorption of over 80% in four consecutive cycles. The adsorption efficacy of NFs to remove Pb in apple juice has reached 76%. It is appropriate and useful to use these nanofibers as a high-efficiency adsorbent in water and food systems based on an analysis of their adsorption properties and how well they work.

Potentially toxic elements (PTEs) are a major concerns from food safety, environmental, and ecological points of view. In this study, the concentration of Arsenic (As), Lead (Pb), Mercury (Hg), Nickel (Ni), Cadmium (Cd), Copper (Cu), Chromium (Cr) and Zinc (Zn) in corn and soybean samples collected from Tehran’s market was investigated by the aid of an Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). Besides, the percentile 95% target hazard quotient (THQ) and carcinogenic risk (CR) for adults’ and children’s consumers were estimated using the Monte Carlo Simulation (MCS) technique. The range concentration of As, Cd, Pb, Ni, Cr, Cu and Zn detected in corn samples was <0.001 to 0.025, <0.001 to 0.003, 0.001 to 0.108, 0.060 to 0.193, 0.212 to 0.363, 0.061 to 0.114, and 1.178 to 1.701 mg/kg, respectively, while the corresponded values for soybean samples were <0.001 to 0.036, 0.001 to 0.005, 0.002 to 0.125, 0.138 to 1.025, 0.055 to 1.054, 0.333 to 0.799, 1.518 to 3.893, mg/kg, respectively. The mean concentration of PTEs in all samples was less than the maximum permitted level recommended by EU standards. The result of the health risk assessment shows that consumers are not at substantial non-carcinogenic and carcinogenic risk due to ingestion of PTEs via consumption of corn and soybean. Consequently, although there is no necessity for urgent action, efforts to sustain these conditions are crucial to warrant public health.