Antimicrobial activity of the LTA zeolite modified by zinc species

Abstract

Metal species supported on zeolites have proven efficient synergistic mechanisms against microorganisms, reducing the overall toxicity. Likewise, the deposition of metals by ultrasound is a method that has drawn attention due to its efficiency, low cost, and environmental friendliness. Hence, the antimicrobial properties of Zinc (Zn) species supported on LTA zeolite (NaA) via a sono-assisted method were explored in this study. Zeolite A modified with Zn species by ion exchange or sono-assisted precipitation of active Zn species (Zn(OH)₂, ZnO, and ZnO₂) was evaluated in a screening experiment by agar diffusion and micro broth assays. Finding that at a concentration of 30 mg/mL, drying the ZnO₂@NaA material activated a mechanism that inhibited the growth of E. faecalis by 100 % while eliminating the drying step, an inverse effect was produced, now inhibiting the growth of E. coli. This sample also presented promising properties as an antimycotic agent inhibiting the growth of C. albicans by 90 % at a concentration of 1 mg/mL. In addition, a viability analysis was performed on fibroblasts, demonstrating a potential toxicity reduction.

This ZnO₂@NaA material holds promise as an antibacterial and antifungal agent. Presenting a novel sono-assisted methodology for tuning the selectivity of inhibition mechanisms for peroxide-containing species in zeolites. This selected zinc-containing zeolitic material (ZnO₂@NaA) was then characterized by UV–Vis, FTIR, Raman spectroscopy SEM, XRD, and ζ-potential, evidencing the presence of ZnO₂ nanoparticles. This study opens perspectives for developing new antimicrobial Zn-containing zeolitic materials through a sono-assisted methodology for increasing selectivity in the inhibition mechanisms.