Sequential galvanic replacement mediated platelet Ru nanozyme for enhanced peroxidase-mimicking efficiency in neutral media to combat gastrointestinal bacterial infection

Nanozymes are nanomaterials that mimic the functions of biological enzymes, offering improved stability and efficacy in biosensing and therapeutics beyond biological enzyme capabilities. As part of advanced nanozyme design and synthesis, we introduced a two-step sequential galvanic replacement reaction to achieve a generally forbidden elemental replacement from Ag to Ru while preserving nanoplate morphology. This synthetic approach was developed to overcome the inherent redox potential limitation that prevents direct substitution of Ag with Ru in conventional galvanic systems. This study introduces the synthesis of a novel Ru nanozyme (RuNZs) with platelet morphology, enhanced by doping with Mn and Ag for improved peroxidase (POD)-mimicking activity at neutral pH. Subsequently, the antibacterial potential of RuNZs was evaluated against gastrointestinal pathogens, Escherichia coli and Salmonella enterica, employing colony-forming unit quantification and direct co-culture analyses. Biocompatibility assessments were conducted through cell viability assays utilizing human cell lines. Peroxidase activity confirmation was achieved via quantification of intracellular reactive oxygen species (ROS) accumulation in HT29 colon cells. This comprehensive investigation delineates the capacity of RuNZs’ peroxidase activity in impeding bacterial proliferation, shedding light on their promising therapeutic implications.