Synthesis and characterization of b-lactam functionalized superparamagnetic Fe3O4@SiO2 nanoparticles as an approach for improvement of antibacterial activity of b-lactams

In this paper, we reported, for the first time, a new multistep method for preparing b-lactam functionalized Fe3O4@SiO2 nanoparticles with high saturation magnetization. The synthesized nanostructures were characterized by FT-IR, XRD, TEM, FE-SEM, TGA, DLS, N2 adsorption–desorption isotherm analysis, elemental analysis, NMR and mass spectroscopy. Also, the magnetic properties of these Fe3O4 nanoparticles allowed the simple separation of these nanoparticles from the reaction mixture by an external magnetic field. b-Lactams (2a–f) and nano Fe3O4@SiO2/b-lactams (3a–f) were tested against Gram-positive S. aureus (ATCC 25923) and Gram-negative Escherichia coli (ATCC 25922) and results showed the minimum inhibitory concentrations (MICs) of 3a–f were less than 2a–f.

β-Lactam; [2‏+2] Cycloaddition; Core shell; Fe3O4@SiO2; Superparamagnetism; Antibacterial activity