Antimicrobial activity of faujasite zeolites doped with silver

The preparation, characterization and antimicrobial activity of faujasite (FAU) zeolites (NaY and NaX) doped with silver are reported. The antimicrobial activity properties were achieved in both FAU zeolites by ion exchange method. The characterization was performed by X-ray diffraction (XRD), Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transformed infrared spectroscopy (FTIR) and chemical analyses. The characterization results indicate that silver were interchanged in the structure of FAU zeolites. Antimicrobial potential of silver zeolites (AgY and AgX) was evaluated using bacteria (Escherichia coli and Bacillus subtilis) and yeast (Saccharomyces cerevisiae and Candida albicans) as sensitive indicator strains. The detected antimicrobial properties were generated by the silver present in the zeolite structure, as confirmed by XPS analysis and antimicrobial activity assays. Both zeolites showed good antimicrobial properties, in particular antibacterial activity, but AgY displayed lower minimum inhibitory concentration (MIC) values than AgX.

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► FAU zeolites doped with silver enhanced the antimicrobial activity of NaY or NaX.
► Antimicrobial potential of Ag–FAU was evaluated using different microorganisms.
► AgY displayed lower minimum inhibitory concentration (MIC) values than AgX.
► Antimicrobial activity of AgY is more pronounced due to the presence of Ag+ ions.