Orientation of Organic Anions in Zn-Al Layered Double Hydroxides with Enhanced Antibacterial Property

Abstract

Layered double hydroxide (LDH)-based nanocomposites, fabricated by interacting LDHs with organic anions, are an emerging and active area in healthcare, environmental remediation, catalysis, and storage. Ciprofloxacin, sulfanilamide, and oxazolidinone, which exhibit antibacterial activity, are successfully intercalated in Zn-Al LDHs through anion exchange method. Synthesis of the precursor was confirmed by Xray diffraction (XRD), transmission electron microscopy (TEM). Intercalation was successfully evaluated from XRD data. It has been found that both the nature and position of aromatic ring substituents effect the value of the basal distance and the host-guest hydrogen bond network. Evidence on interactions of intercalated anions with the inorganic layer has been confirmed from Fourier transform infrared absorption spectroscopy. Morphology of composites was studied by field emission scanning electron microscopy, and thermal stability was studied by thermogravimetry and differential thermal analysis. The novel nanocomposites demonstrated antibacterial activity against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The designed organic-inorganic fusions may offer a promising antimicrobial nanomaterial for varied applications.