Antibacterial Activities of Selenium-Modified Zn/Al Layered Double Hydroxide and Its Polycarbazole Hybrid

This study investigated the antibacterial activities of Se-Al/Zn layered double hydroxide (LDH) and its polycarbazole (PCz) hybrid against Gram-positive Bacillus subtilis and Gram-negative E. coli cells. Antibacterial performances were evaluated using zone of inhibition assays, viable cell counting, and measurement of metabolic activity based on intracellular ATP levels. The collective results showed that both materials exhibited significant antibacterial activity, with PCz–Se–Al/Zn LDH demonstrating enhanced antibacterial activity compared to Se–Al/Zn LDH. Fluorescent live/dead staining and scanning electron microscopy revealed that treatment with either material resulted in loss of metabolic activity and induction of a non-culturable state in bacterial cells, without observable membrane damage or pronounced morphological changes. Possible antibacterial mechanisms of action associated with LDH and PCz–LDH systems are briefly discussed.