# Effect of Nanoparticles Type and Content on the Antimicrobial Activity of Magnetoelectric Polymer‐Based Composites

## TL;DR

This paper explores how magnetoelectric nanocomposites with different nanoparticles can inhibit bacterial growth when stimulated by magnetic fields.

## Contribution

The study introduces magnetoelectric nanocomposites that show enhanced antimicrobial activity under magnetic stimulation.

## Key findings

- Nanocomposites with 20% CoFe2O4 nanoparticles showed significant inhibition of E. coli and S. aureus at 1 Hz magnetic stimulation.
- Magnetic stimulation increased antimicrobial effectiveness compared to static conditions.
- P(VDF-TrFE) nanocomposites with CFO nanoparticles are promising for antimicrobial surfaces in medical and public settings.

## Abstract

Antimicrobial materials are essential for the development of coatings for high traffic surfaces to prevent the adhesion and proliferation of microorganisms, playing a crucial role in infection control. In this study, different magnetoelectric nanocomposites exhibiting antimicrobial activity upon magnetic stimulation were developed by solvent casting. The nanocomposites, composed of poly(vinylidene fluoride‐co‐trifluoroethylene) [P(VDF‐TrFE)] with different contents (10 and 20% wt) of CoFe2O4 (CFO) or Fe3O4 nanoparticles, were developed to respond to a variable magnetic field, mechanically stimulating the piezoelectric component of the material and inducing surface potential variations. The antimicrobial properties of these materials were evaluated by exposing them to different magnetic frequencies (0.3 and 1 Hz) in a custom‐made magnetic bioreactor. The growth of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was significantly inhibited, particularly in the P(VDF‐TrFE) nanocomposite with 20% CFO NPs, under magnetic stimulation at 1 Hz (bacterial cell viability ≈15%) compared to static conditions (bacterial cell viability ≈35%). This study highlights the potential of magnetic stimulation, in combination with magnetoelectric materials, as an effective strategy for the development of antimicrobial surfaces.

Magnetoelectric P(VDF‐TrFE) nanocomposites containing CFO or Fe3O4 nanoparticles were developed to generate electroactive microenvironments under magnetic stimulation. At 1 Hz, particularly with 20% CFO, strong antimicrobial effects were observed against E. coli and S. aureus. This approach highlights the potential of magnetically activated surfaces to inhibit microbial adhesion and support infection control in medical and public settings.