Selenium-polycarbazole modified ldhs: dual-mode antibacterial catalysts with tunable reactive oxygen species generation

Layered double hydroxides (LDHs) are versatile materials with wide-ranging uses in catalysis, drug delivery, and antimicrobial systems due to their tunable layered structure. In this study, selenium (Se)-modified Al/Zn LDHs were developed to enhance bioactivity by utilizing Se’s strong antioxidant and antimicrobial properties. The LDHs were further functionalized with polycarbazole (PCz) at 0.2–1 wt% and characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) with elemental mapping confirming successful incorporation of Se and PCz. Electrochemical studies showed that the polymer-coated LDH catalyst enables selective in situ generation of hydrogen peroxide (H₂O₂) and sustained reactive oxygen species (ROS) production under physiological and mildly alkaline conditions. This tunable ROS activity indicates controllable antibacterial potential. Zone inhibition tests demonstrated that PCz-modified Se–LDH nanohybrids exhibited stronger antibacterial effects against Bacillus subtilis and Escherichia coli than unmodified samples, highlighting their promise as advanced, tunable antimicrobial materials for biomedical and environmental applications.