Antimicrobial activity of Iron oxide nanoparticles (IONPs) functionalized with anthocyanin extracted from blackcurrants (Ribes nigrum)

Iron oxide nanoparticles (IONPs) have attracted significant attention in recent years due to their versatility and facile synthesis. They are considered a promising platform for the development of novel antimicrobial delivery systems, particularly in the context of the emerging antibiotic-resistant pathogens that continue to pose a global threat. This study aims to investigate the potential antimicrobial efficacy of IONPs, synthesized using the co-precipitation method and functionalized with anthocyanins, which act as bioactive agents that have been extracted from
blackcurrants (Ribes nigrum), forming a core–shell architecture. Anthocyanins are pH-dependent phenolic pigments, naturally occurring in various berries and fruits, that exhibit a strong antioxidant activity, strongly associated with antimicrobial and anti-cancer properties.
The resulting bio-composite was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), which confirmed its spherical morphology, with an average particle size of approximately 10 nm, while Fourier-transform infrared spectroscopy (FTIR) demonstrated the successful organic coating of the nanoparticles. Furthermore, the antimicrobial activity of the functionalized IONPs was assessed against both Gram-positive and Gram-negative bacteria using the disk-diffusion method and broth microdilution assays in 96 microtiter plates. The obtained results highlight the potential of anthocyanin-functionalized IONPs as sustainable, plant-derived antimicrobial agents.
By combining natural bioactive compounds with biocompatible nano-delivery systems, this approach offers a promising strategy for developing alternative antimicrobial therapies capable of overcoming resistance mechanisms.