A Comprehensive Study on Enhancing Microbicidal Activity of Pure and Ion-Exchanged Zeolites Through Structural and Chemical Determinants

Abstract

Zeolites are crystalline aluminosilicate materials known for their unique structures and small pores, making them highly suitable for various applications, including antimicrobial uses. Their porous surfaces enable them to act as carriers for metal ions, enhancing their antibacterial potential. A recent comprehensive review of the literature assessed the antibacterial activity of both natural and synthetic zeolites, with a specific focus on their performance after being modified with metal ions. The study confirmed that while unmodified zeolites possess some inherent antibacterial properties, their effectiveness is generally limited to high concentrations. In contrast, zeolites modified with metal ions, such as silver (Ag), copper (Cu), or zinc (Zn), demonstrate significantly enhanced antimicrobial effects at much lower concentrations. Among the metal-modified zeolites, Ag-treated zeolite A (ZA) emerged as the most effective, exhibiting a remarkably low minimum inhibitory concentration (MIC) of just 16 µg/mL against various bacterial strains. This heightened activity is attributed to the controlled release of Ag ions and the high ion-exchange capacity of ZA, which allows for sustained antimicrobial action. These findings suggest that metal-exchanged zeolites, particularly those with high ion-retention capabilities, hold strong potential as long-lasting and efficient antimicrobial agents. Such materials could be valuable in medical, environmental, and industrial applications, especially where bacterial resistance is a growing concern.