Interactions of Fe–N–S Co-Doped Porous Carbons with Bacteria: Sorption Effect and Enzyme-Like Properties

Abstract

Carbon-based (nano)materials doped with transition metals, nitrogen and other heteroatoms are considered active heterogeneous catalysts in a wide range of chemical processes. Recently they have been scrutinized as artificial enzymes since they can catalyze proton-coupled electron transfer reactions vital for living organisms. Herein, interactions between Gram-positive and Gram-negative bacteria and either metal-free N and/or S doped or metal containing Fe−N−S co-doped porous carbons are studied. The Fe- and N-co-doped porous carbons (Fe−N−C) exhibit enhanced affinity toward bacteria as they show the highest adsorption capacity. Fe−N−C materials also show the strongest influence on the bacteria viability with visible toxic effect. Both types of bacteria studied reacted to the presence of Fe-doped carbons in a similar manner, showing a decrease in dehydrogenases activity in comparison to controls. The N-coordinated iron-doped carbons (Fe−N−C) may exhibit oxidase/peroxidase-like activity and activate O2 dissolved in the solution and/or oxygen-containing species released by the bacteria (e.g., H2O2) to yield highly bactericidal reactive oxygen species. As Fe/N/ and/or S-doped carbon materials efficiently adsorb bacteria exhibiting simultaneously antibacterial properties, they can be applied, inter alia, as microbiological filters with enhanced biofouling resistance.

Biomedical applications of iron sulfide-based nanozymes

“…For example, it is hypothesized that Fe-N-S co-doped porous carbons promoted oxygen reduction by catalyzing the transfer of electrons and protons from organic matter to oxygen. Hence, the reduction product contained •O − 2 (Borkowski et al, 2020). In addition to POD-like activity, Xu and co-workers proved that nFeS possesses catalase activity which can decompose H 2 O 2 into oxygen (Xu et al, 2018).…”