Abrading-Induced Breakdown of Ag Nanoparticles into Atomically Dispersed Ag for Enhancing Antimicrobial Performance

Abstract

Silver is among the most essential antimicrobial agents. Increasing the efficacy of silver-based antimicrobial materials will reduce operating costs. Herein, we show that mechanical abrading causes atomization of Ag nanoparticles (AgNPs) into atomically dispersed Ag (AgSAs) on the surfaces of an oxide-mineral support, which eventually boosts the antibacterial efficacy considerably. This approach is straightforward, scalable, and applicable to a wide range of oxide-mineral supports; additionally, it does not require any chemical additives and operates under ambient conditions. The obtained AgSAs-loaded γ-Al2O3 inactivated Escherichia coli (E. coli) five times as fast as the original AgNPs-loaded γ-Al2O3. It can be utilized over 10 runs with minimal efficiency loss. The structural characterizations indicate that AgSAs exhibit a nominal charge of 0 and are anchored at the doubly bridging OH on the γ-Al2O3 surfaces. Mechanism studies demonstrate that AgSAs, like AgNPs, damage bacterial cell wall integrity, but they release Ag+ and superoxide substantially faster. This work not only provides a simple method for manufacturing AgSAs-based materials but also shows that AgSAs have better antibacterial properties than the AgNPs counterpart.

Accumulation of Ag(0) Single Atoms at Water/Mineral Interfaces during Sunlight-Induced Reduction of Ionic Ag by Phenolic DOM

“…Individual bright objects with a diameter of approximately 0.3 nm appear to be randomly scattered throughout the surfaces of the Al 2 O 3 support. Considering the remarkable difference in Z-contrast between Ag and Al/O, the little bright spots can be identified as Ag atoms . According to the different regional investigations, Ag-SAs account for the majority of the subnanometer species in Ag/Al 2 O 3 –PhOH (Figure C) and Ag/Al 2 O 3 –HA (Figure D), whereas small Ag(0) clusters are rare.…”

“…For instance, because Ag-SAs lack SPR absorption, sunlight less impacts their behavior. Ag-SAs can release Ag + and superoxide more quickly and may be more toxic to microbes than AgNPs . Furthermore, metal single atoms may have catalytic activity more substantial or even different than that of the corresponding nanoparticles.…”

“…Ag-SAs, as a particular form of Ag(0), have very high surface energy and are expected to interact strongly with the surfaces of particulates, such as minerals. Because of its high activity, Ag-SAs are prone to oxidation, which releases Ag + . Furthermore, due to atomic dispersion, the number of Ag-SAs may be significantly greater than that of AgNPs.…”

Efficient V-Shaped Substrate for Surface and Volume Enhanced Raman Spectroscopic Analysis of Bioaerosol: Prevention from Potential Health Risk

“…Nevertheless, as the time further increases, the secretion of the bacteria will no longer increase or even decrease. This can be explained by the deactivation process where the bacteria will be greatly decomposed and dead due to the great damage induced by the collision and poison of the AgNPs to the bacteria, 46 thus leading to a certain reduction in the Raman signal intensity of bacteria.…”