Visible-Light-Triggered Reactive-Oxygen-Species-Mediated Antibacterial Activity of Peroxidase-Mimic CuO Nanorods

Abstract

The rapid emergence of antibiotic-resistant bacterial strains warrants new strategies for infection control. NanoZymes are emerging as a new class of catalytic nanomaterials that mimic the biological action of natural enzymes. The development of photoactive NanoZymes offers a promising avenue to use light as a “trigger” to modulate the bacterial activity. Visible light activity is particularly desirable because it contributes to 44% of the total solar energy. Here we show that the favorable band structure of a CuO-nanorod-based NanoZyme catalyst (band gap of 1.44 eV) allows visible light to control the antibacterial activity. Photomodulation of the peroxidase-mimic activity of CuO nanorods enhances its affinity to H2O2, thereby remarkably accelerating the production of reactive oxygen species (ROS) by 20 times. This photoinduced NanoZyme-mediated ROS production catalyzes physical damage to the bacterial cells, thereby enhancing the antibacterial performance against Gram-negative-indicator bacteria Escherichia coli.

Antibiotic‐Free Antibacterial Strategies Enabled by Nanomaterials: Progress and Perspectives

“…Another class of sunlight‐triggered antibacterial nanomaterials mimics the actions of peroxidase to catalyze the production of ROS. CuO nanorods (NRs) with an appropriate energy‐band structure were reported to generate hydroxyl radicals upon photoexcitation with visible light, contributing to the peroxidase‐like property and improved antibacterial performance (Figure f,g) . To date, reports on sunlight‐triggered nanomaterials are limited.…”

“…Copyright 2016, American Chemical Society. (f,g) Reproduced with permission . Copyright 2018, American Chemical Society.…”

Antimicrobial Metal Nanomaterials: From Passive to Stimuli‐Activated Applications

“…In conjunction with TiO 2 , other semiconductor metal oxides with similarly small bandgaps have been investigated for their potential antimicrobial properties [ 114,189–202 ] (see Table 2 ). For example, Seven et al demonstrated a significant reduction in the viability of E. coli , Pseudomonas aeruginosa and Staphylococcus aureus cells in the presence of ZnO nanoparticles under irradiation of a broad‐range UV lamp (250–400 nm).…”

“…[ 198 ] In the visible light range, Singh and co‐workers demonstrated ROS production and associated antibacterial activity against E. coli , using CuO nanorods. [ 199 ] In a comprehensive study, Zhang et al compared the generation of ROS and subsequent antibacterial activity of a wide range of metal nanoparticles and determined AgNPs were the most effective, followed by SiNPs, NiNPs, and AuNPs in descending order. [ 114 ] This was partially because AgNPs generate superoxide and hydroxyl free radicals, whereas the other three metal oxides only produce singlet oxygen species.…”

Progress and Trend on the Regulation Methods for Nanozyme Activity and Its Application

“…However, most of the existing antibacterial mechanism was focused on the above first one. Karim et al reported that CuO nanorods could serve as high-efficiency antibacterial agents under light illumination, which causes a 20 times enhancement of the •OH production rate compared with the dark condition [84]. Yan's group first demonstrated a zinc-based zeolitic-imidazolate-framework (ZIF-8) derived Zn-N-C single-atom nanozyme (SAzyme) that is considered as a high therapeutic effect single-atom catalyst for wound antibacterial application ( Figure 5) [85].…”