Silver phosphate nanostructures as functional materials for antimicrobial applications

The antimicrobial effects of silver nanomaterials have been extensively studied over time. However, concerns regarding their nano-safety have recently emerged, particularly for particles with a diameter below 50 nm. For this reason, part of the scientific community working on nano- and micro-antimicrobials is now focusing on developing alternative materials that are both eco-friendly and less toxic, such as silver phosphate. In this study, cubic Ag3PO4 particles were synthesized via a precipitation method under alkaline conditions, and the influence of reaction time and degree of completion was investigated. The samples were characterized by transmission electron microscopy (TEM) and Fourier-transform infrared spectroscopy in attenuated total reflection mode (ATR-FT-IR), revealing that a reaction time of 45 min at 70% or 90% completion is sufficient to achieve complete nucleation and growth of the particles. Finally, the antibacterial activity of the resulting materials was evaluated against Escherichia coli and Staphylococcus aureus, demonstrating that Ag3PO4 particles exert a strong antimicrobial effect even at 0.5 mg/mL.