ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Study of the biocidal capacity of ferromagnetic Fe₃O₄ nanoparticles combined with H₂O₂: synthesis and optimization of key variables

Lamia Hejji, Antonio J. Muñoz, Abdelmonaim Azzouz, Luis P. Villarejo, Eulogio Castro, Manuel Moya, Francisco Espínola, and Enrique Rodríguez-Castellón

Department of Chemical, Environmental, And Materials Engineering, University of Jaén, Jaén, Spain

E-mail: aazzouz@uae.ac.ma

Received: 15 July 2025  Accepted: 11 August 2025

Abstract:

This study explores a sustainable synthesis route for magnetic nanomaterials with potential applications in biotechnological fields. The objective was to develop a ferromagnetic nanomaterial (Fe₃O₄-NPs) capable of catalyzing the generation of reactive oxygen species (ROS) in the presence of H₂O₂. The biocidal activity of these nanoparticles was tested against four bacterial strains. Fe₃O₄-NPs were synthesized using a simple, reproducible method that ensured consistent morphology and size (125–175 nm). Comprehensive characterization was conducted using advanced techniques. To optimize the conditions for ROS generation, a 4-factor Box–Behnken design was employed and analyzed through response surface methodology, yielding the optimal parameters: pH 6, temperature 42 °C, and concentrations of 160 µg/mL for Fe₃O₄-NPs and 0.136 µg/mL for H₂O₂. Biocidal tests revealed a significant killing effect on Bacillus cereus, with up to a 60-fold reduction in the H₂O₂ concentration needed to achieve the same effect. Strong inhibition was also observed for other bacterial strains. The results demonstrate the effective biocidal activity of the Fe₃O₄-NPs/H₂O₂ combination. The magnetic properties of the nanoparticles facilitated their transport and accumulation within cells, further enhancing their biocidal effect. This study underscores the potential of Fe₃O₄-NPs in biomedicine, contributing to advancements in the fight against antibiotic resistance. This study highlights the potential of Fe₃O₄-NPs in biomedicine and provides interesting new insights, such as optimizing variables for synthesizing reactive oxygen species using response surface methodology. Additionally, the biocidal effect of the Fe₃O₄-NPs/H₂O₂ combination was analyzed using 12-h growth curves, which reinforced the results. These findings are intended to contribute to progress in the fight against antibiotic resistance.

Graphical abstract

Keywords: Reactive oxygen species; Biocidal activity; Fe3O4-NPs; H2O2; Fenton-like reaction; Response surface methodology

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-025-04308-w

Chemical Papers 79 (11) 8089–8103 (2025)