Glucose-activated enzyme-nanozyme cascade nanoflowers for antibacterial surfaces on cement mortar

초록

Bacterial contamination and biofilm formation on material surfaces remain major challenges in aqueous environments. Herein, we report a glucose-activated antibacterial cement surface created by immobilizing enzyme-nanozyme cascade nanoflowers composed of glucose oxidase and copper phosphate (GOx-Cu NFs) onto cement mortar. In this system, glucose oxidase catalyzes glucose oxidation to generate hydrogen peroxide (H2O2), which is subsequently converted into reactive oxygen species through the peroxidase-like catalytic activity of the Cu-based nanoflowers, enabling efficient antibacterial activity. The GOx-Cu NFs exhibited strong bactericidal performance, achieving 99.9% killing of the Gram-positive bacterium Staphylococcus aureus and the Gramnegative sulfate-oxidizing bacterium Thiobacillus novellus at concentrations as low as 0.030 mg mL- 1 and 0.015 mg mL- 1, respectively, at an initial bacterial density of 104 CFU mL- 1. Importantly, the nanoflowers could be successfully immobilized onto cement mortar surfaces, where clear inhibition zones of 6.23 +/- 2.77 mm for S. aureus and 5.78 +/- 2.95 mm for T. novellus were observed. The immobilized nanoflowers retained antibacterial functionality under aqueous storage conditions for at least 15 days. These results demonstrate a practical strategy for engineering reactive antibacterial cement surfaces and highlight the potential of enzyme-nanozyme hybrid nanoflowers as antibacterial coatings for solid materials exposed to aqueous environments.

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