Chelation of silver ions into a chemically stable and scalable aluminum-based metal−organic framework for highly efficient and recyclable sterilization

The development of efficient and long-duration antimicrobial agents remains an important and challenging goal for public health safety. Current silver-containing antimicrobials commonly suffer from the limited silver (Ag) content or uncontrolled release of Ag + ions, leading to restricted bactericidal activity and duration. Herein, we report an example of chelating Ag(I) into a highly stable and scalable aluminum-based MOF (Ag + @MOF-303) for achieving highly efficient sterilization. Due to the edge-to-edge arrangement of pyrazole rings with a short N − N distance of 3.4 Å, Ag + ions can be precisely chelated into the MOF-303 framework with a controlled amount of 0.28 g Ag g MOF −1 . The resulting material Ag + @MOF-303 was thoroughly characterized by powder X-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy. Bactericidal activity experiments revealed that Ag + @MOF-303 can efficiently inhibit a wide range of bacteria, with a minimal inhibitory concentration of 31.25 μg mL −1 and a minimum bactericidal concentration of 62.5 μg mL −1 against the Gram-negative strain Escherichia coli , corresponding to silver content of 8.75 and 17.5 μg mL −1 , respectively. The controlled Ag + release from Ag + @MOF-303 was monitored to show a gradual release of 26.1 % of its total silver content over 7 days. Benefiting from its highly stable framework, this material after sterilization could be easily regenerated by the re-metalation of Ag + ions into MOF-303, indicating its unique reutilization and sustainability for sterilization applications.