Bimetallic CuCo2S4 Nanozymes with Enhanced Peroxidase Activity at Neutral pH for Combating Burn Infections

Graphical Cleaning wounds : A bimetallic CuCo 2 S 4 nanozyme exhibits enhanced peroxidase-like activity at neutral pH, and can convert H 2 O 2 into highly toxic hydroxyl radicals for killing bacteria. The CuCo 2 S 4 nanozyme effectively facilitates the healing of burn wounds infected with drug-resistant bacteria. Peroxidase-mimicking nanozymes that can generate toxic hydroxyl radicals ( . OH) hold great promise as antibacterial alternatives. However, most of them display optimal performance under strongly acidic conditions (pH 3–4), and are thus not feasible for many medical uses, including burn infections with a wound pH close to neutral. Herein, we report a copper-based nanozyme (CuCo 2 S 4 ) that exhibits intrinsic peroxidase-like activity and can convert H 2 O 2 into . OH at neutral pH. In particular, bimetallic CuCo 2 S 4 nanoparticles (NPs) exhibited enhanced peroxidase-like activity and antibacterial capacity, superior to that of the corresponding monometallic CuS and CoS NPs. The CuCo 2 S 4 nanozymes possessed excellent ability to kill various bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). Furthermore, this CuCo 2 S 4 nanozymes could effectively disrupt MRSA biofilms in vitro and accelerate MRSA-infected burn healing in vivo. This work provides a new peroxidase mimic to combat bacteria in neutral pH milieu and this CuCo 2 S 4 nanozyme could be a promising antibacterial agent for the treatment of burn infections.