Au-Au/IrO2@Cu(PABA) Reactor with Tandem Enzyme-Mimicking Catalytic Activity for Organic Dye Degradation and Antibacterial Application

Herein, a Au-Au/IrO2 nanocomposite with tandem enzyme-mimicking activity was innovatively synthesized, which can show outstanding glucose oxidase (GOx)- like activity and peroxidase-like activity simultaneously under neutral conditions. Moreover, a Au-Au/IrO2@Cu(PABA) reactor was prepared via encapsulation of the Au-Au/IrO2 nanocomposite in a Cu(PABA) metal organic framework. The reactor not only exhibits excellent organic solvent stability, acid resistance, and reusability but also displays better cascade reaction catalytic efficiency (k(cat)/K-m = 148.86 min(-1) mM(-1)) than the natural free enzyme system (GOx/HRP) (k(cat)/K-m = 98.20 min(-1) mM(-1)) and Au-Au/IrO2 nanocomposite (k(cat)/K-m = 135.24 min(-1) mM(-1)). In addition, it is found that the reactor can catalyze glucose or dissolved oxygen to produce active oxygen species (ROS) including HO, O-1(2), and O-2(-center dot) through its enzyme-mimicking activity. Finally, the novel reactor was successfully used in organic dye degradation and antibacterial application. The results show that it can effectively degrade methyl orange, methylene blue, and rhodamine B, which all can reach a degradation rate of nearly 100% after interacting with Au-Au/IrO2@ Cu (PABA) for 3.5 h. Furthermore, the reactor also exhibits excellent antibacterial activity, so as to achieve a complete bactericidal effect to Staphylococcus aureus and Escherichia coli at a concentration of 12.5 mu g mL(-1).

Automated summary

The innovative synthesis of Au-Au/IrO2 nanocomposite with tandem enzyme-mimicking activity leads to the preparation of a highly stable and reusable Au-Au/IrO2@Cu(PABA) reactor. This reactor exhibits excellent catalytic efficiency, organic solvent stability, acid resistance, and antibacterial activity, making it suitable for organic dye degradation and antibacterial applications.