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 Ag 3 PO 4 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 Ag 3 PO 4 particles exert a strong antimicrobial effect even at 0.5 mg/mL.