Green synthesis of iron oxide nanoparticles using <i>Ceratonia siliqua L.</i> aqueous extract: improvement of colloidal stability by optimizing synthesis parameters, and evaluation of antibacterial activity against Gram-positive and Gram-negative bacteria

Abstract This study focused on the colloidal stability enhancement of iron oxide nanoparticles synthesized using aqueous extract Ceratonia siliqua L. (carob pod) by optimizing synthesis parameters. The parameters were determined as concentration ions, extract, pH temperature, stirring rate, and reaction time. significance studied factors in controlling particle size distribution was quantitatively evaluated via analysis variance (ANOVA). Iron produced with an average zeta potential +41 ± 0.8 mV, hydrodynamic 78 22 nm, a polydispersity value 0.42 0.06, respectively. As result measuring potential, it that maintained for 3 months. Green (gIONPs) showed inhibition zones 24.27 0.12 mm 20.83 0.11 250 mg/mL against Gram-negative ( Escherichia coli ) Gram-positive Staphylococcus aureus bacterial strains, S. susceptible to gIONPs according standard antibiotics Cefotaxime (≥23 mm), Tetracycline (≥19 Gentamicin (≥15 Cefoxitin (≥22 mm). E. mm) but resistance (15–22 (≤21 antibiotics. suggests green could be used antimicrobial agent promising candidate usage sensor, biomedical, electronics applications being highly stable structure.