La-Doped CeO ₂ Quantum Dots: Novel Dye Degrader, Antibacterial Activity, and <i>In Silico</i> Molecular Docking Analysis

Abstract

The current work demonstrates a novel synthesis of different concentrations of La-doped (2, 4, and 6 wt %) CeO₂ quantum dots (QDs) using a hydrothermal approach. This research aimed to examine the dye degradation efficiency, antibacterial activity, and <i>in silico</i> molecular docking analysis of La-doped CeO₂ QDs. The structure, elemental composition, optical properties, <i>d</i>-spacing, and morphological features of QDs were examined using various methods. XRD spectra exhibited the cubic structure of CeO₂, and the crystallinity was suppressed upon La doping. TEM revealed the formation of cubic-shaped QDs of CeO₂, and the incorporation of La decreased agglomeration. UV-vis absorption spectra showed a red shift upon La doping, assigned to a decrease in band gap energy. 6% La-doped CeO₂ showed significant antibacterial activity against <i>Escherichia coli</i> at higher concentrations in comparison to ciprofloxacin. La-CeO₂ was proposed as a putative inhibitor of β-lactamase _{<i>E. coli</i>} and DNA gyrase _{<i>E. coli</i>} relying on the outcomes of a molecular docking analysis that was in improved accord with <i>in vitro</i> bactericidal activity. Moreover, the prepared QDs exhibited a remarkable photocatalytic degradation of methylene blue in a basic medium.