Biogenic Silver Nanoparticles/Mg-Al Layered Double Hydroxides with Peroxidase-like Activity for Mercury Detection and Antibacterial Activity

Over the past decade, the attention of researchers has been drawn to materials with enzyme-like properties to substitute natural enzymes. The ability of nanomaterials to mimic enzymes makes them excellent enzyme mimics; nevertheless, there is a wide berth for improving their activity and providing a platform to heighten their potential. Herein, we report a green and facile route for Tectona grandis leaves extract-assisted synthesis of silver nanoparticles (Ag NPs) decorated on Mg-Al layered double hydroxides (Mg-Al-OH@TGLE-AgNPs) as a nanocatalyst. The Mg-Al-OH@TGLE-AgNPs nanocatalyst was well characterized, and the average crystallite size of the Ag NPs was found to be 7.92 nm. The peroxidase-like activity in the oxidation of o-phenylenediamine in the presence of H₂O₂ was found to be an intrinsic property of the Mg-Al-OH@TGLE-AgNPs nanocatalyst. In addition, the use of the Mg-Al-OH@TGLE-AgNPs nanocatalyst was extended towards the quantification of Hg²⁺ ions which showed a wide linearity in the concentration range of 80-400 μM with a limit of detection of 0.2 nM. Additionally, the synergistic medicinal property of Ag NPs and the phytochemicals present in the Tectona grandis leaves extract demonstrated notable antibacterial activity for the Mg-Al-OH@TGLE-AgNPs nanocatalyst against Gram-negative Escherichia coli and Gram-positive Bacillus cereus.