A novel Ag/Ag 3 PO 4 ‐IRMOF‐1 nanocomposite for antibacterial application in the dark and under visible light irradiation

MOF‐5 that sometimes called IRMOF‐1 has been intensively studied in recent years to develop efficient photocatalyst to degrade refractory organics and inactivate bacteria for wastewater treatment. In the present work, Ag/Ag 3 PO 4 nanoparticles incorporated in IRMOF‐1 was successfully prepared via hydrothermal approach. The antibacterial activity of synthesized materials (IRMOF‐1, Ag/Ag 3 PO 4 nanoparticles and Ag/Ag 3 PO 4 ‐IRMOF‐1 nanocomposite was compared against two types of bacteria ( Escherichia coli (E. coil) as Gram negative and Staphylococcus aureus ( S. aureus ) as Gram‐positive bacteria). The deactivation of the bacteria by the prepared material was measured in the dark and under visible light irradiation. The antibacterial activity of synthesized samples was investigated by determining the minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC), growth inhibition assay and inhibition zone. The Ag/Ag 3 PO 4 ‐IRMOF‐1 nanocomposite exhibited stronger antibacterial activities than the Ag/Ag 3 PO 4 nanoparticles and IRMOF‐1 at all tested bacteria types. Based on inhibition zone, without any light irradiation, Ag/Ag 3 PO 4 ‐IRMOF‐1 nanocomposite showed activity toward E. coil , but in presence of light nanocomposite depicted activity toward S. aureus . The results demonstrated that antibacterial activity of all synthesized samples in the dark and light against S. aureus bacteria was more than E. coil bacteria. The antibacterial activity mechanism was due to sustained‐release of silver ions in the dark and reactive oxygen species (ROS) under visible light. The bioactivity of IRMOF‐1 was related to the degradation of the its structure and the release of Zn 2+ ions into the culture medium that bind to the cell wall and deactivation bacteria.