Light‐activated oxidize‐mimicking nanozyme for inhibition of pathogenic Escherichia coli

Abstract

Here we demonstrate the nanozyme properties of histidine‐containing carbon nanodots as externally tunable antibacterial agents through irradiation with visible (VIS) light. The correlative (light and electron) microscopic analysis of treated Escherichia coli O157:H7 revealed that the positive charged carbon nanoparticles might readily adsorb at slightly acid pH on the negative charged cellular envelope of bacteria, and thus, inhibit their growth with over 80% efficiency under illumination with VIS light. The reason was that under VIS irradiation in the range 400–500 nm the adsorbed nanoparticles behaved as effective oxidase‐mimicking enzymes and generated reactive oxygen species on the labeled cells. Thus, the light‐activated artificial nanozyme caused serious physical damaging of bacterial envelope, which was leading to irreversible cellular inhibition. The outcomes of this study are likely to broaden the scope of designed photoactive carbon nanozymes as powerful antibacterial agents against the emergence of antibiotic and multidrug‐resistant strains, as well as proposing of new strategies for infection control.

Plant Photocatalysts: Photoinduced Oxidation and Reduction Abilities of Plant Leaf Ashes under Solar Light

“…For instance, we found that adding a small amount of GeO2 powders into the reaction solution signif- There are a wide variety of compounds in the plant leaf ashes; some of them could be potential efficiency photocatalysts. The existence of different ions may also promote photocatalytic activity, as mentioned in the literature [60,61]. Very interestingly, after the washing of the ashes, the decrease in the photodegradation yield proved the promotion roles of soluble ions in ashes (Figure 3).…”

Solvent‐Free Synthesis of S,N‐Doped Carbon Dots for Extended Visible‐Light‐Induced Oxidase‐Mimicking Activities and Antimicrobial Applications

“…In another work, Saito et al. have also observed light‐activated oxidase mimicking properties from histidine‐doped carbon dots with visible light irradiation in the range of 400–500 nm [8] . The usage of high energy UV or blue light increases the minimal invasiveness limit for various biomedical applications.…”

“…[7] In another work, Saito et al have also observed lightactivated oxidase mimicking properties from histidine-doped carbon dots with visible light irradiation in the range of 400-500 nm. [8] The usage of high energy UV or blue light increases the minimal invasiveness limit for various biomedical applications. Recently, Liu and coworkers also reported an approach to extend the visible light absorption of carbon dots by illuminating the carbon dots with 365 nm wavelength LED before photo-oxidase activity; however, this process requires another post-synthetic treatment.…”