Bioinspired construction of ATP/Co-Al-Zn LDH nanozyme with enhanced peroxidase-mimic performance for efficient bactericidal activity through membrane disruption.

In recent years, overuse of antibiotics has led to emerging antibiotic-resistant strains of bacteria. Consequently, creating new, highly productive antibacterial agents is crucial. In this work, we synthesized copper-aluminum-zinc layered double hydroxide (Co-Al-Zn LDH) and modified it using adenosine triphosphate. After characterization, the enzyme-like activity of the prepared particles was evaluated. The results indicated peroxidase-mimic performance of ATP/Co-Al-Zn LDH with K values of 0.38 mM and 1.69 mM for TMB (3,3',5,5'-tetramethylbenzidine) and hydrogen peroxide (HO), respectively, which were lower than that of horseradish peroxidase. The highest peroxidase-like activity of ATP/Co-Al-Zn LDH was achieved at 20 °C, pH 4, with a 1.02 mg/mL catalyst, 231 μM TMB, and 1.9 mM HO. The bactericidal activity of the developed nanozyme was studied against E. coli and S. aureus. The peroxidase-mimic nanozyme decomposes HO and generates free radicals to kill bacteria in vitro. The minimum inhibitory concentration (MIC) of ATP/Co-Al-Zn LDH was 15 μg/mL and 20 μg/mL for S. aureus and E. coli, respectively. The morphological characteristics of the nanozyme-treated bacterial cells showed dramatic changes in bacterial morphology. Our results revealed higher antibacterial activity of ATP/Co-Al-Zn LDH against S. aureus. Therefore, the developed nanozyme could serve as a substitute for conventional antibiotics.