Comparative Evaluation of Boron, Aluminum, and Silicon Nanoparticles for Antibiofilm and Antimicrobial Applications: Insights into Alternative Strategies

Abstract Food-contact surfaces represent critical reservoirs for microbial contamination in food-related environments. In this study, food-borne microorganisms were isolated from contact surfaces of domestic refrigerators and food-processing facilities and identified using phenotypic and genotypic approaches. The antimicrobial and antibiofilm activities of boron (B), aluminum (Al), and silicon (Si) nanoparticles (NPs) were evaluated against the isolated microorganisms using a broth microdilution assay in 96-well microplates. Cytotoxicity was assessed by the MTT assay on normal human dermal fibroblast (BJ) and human intestinal epithelial (Caco-2) cell lines. Microbiological analyses revealed that a considerable proportion of sampled surfaces did not meet accepted hygiene criteria, highlighting the need for improved sanitation strategies and supplementary antimicrobial interventions. Among the tested nanomaterials, Al NPs exhibited the highest antibacterial and antibiofilm activity, whereas none of the NPs showed antifungal activity against mold cultures. Minimum inhibitory concentration (MIC) values ranged from 1.25 to 10 mg/mL for bacterial strains and from 3.75 to 15 mg/mL for yeast isolates, depending on the nanoparticle type and microorganism. Cytotoxicity assays demonstrated dose-dependent effects on BJ cells for all NPs (IC 50 values of 93.3, 242.5, and 1259.2 μg/mL for B, Al, and Si NPs, respectively), while only B NPs exhibited cytotoxicity toward Caco-2 cells (IC 50 : 77.9 μg/mL). Overall, the findings indicate that especially Al-based NPs may serve as promising supplementary antimicrobial agents for improving hygiene in food-related environments, provided that their safety profiles are carefully considered. Graphical Abstract