Ferroxidase-like and antibacterial activity of PtCu alloy nanoparticles

Abstract

Many metal nanoparticles are reported to have intrinsic enzyme-like activities and offer great potential in chemical and biomedical applications. In this study, PtCu alloy nanoparticles (NPs), synthesized through hydrothermal treatment of Cu²⁺ and Pt²⁺ in an aqueous solution, were evaluated for ferroxidase-like and antibacterial activity. Electron spin resonance (ESR) spectroscopy and colorimetric methods were used to demonstrate that PtCu NPs exhibited strong ferroxidase-like activity in a weakly acidic environment and that this activity was not affected by the presence of most other ions, except silver. Based on the color reaction of salicylic acid in the presence of Fe³⁺, we tested the ferroxidase-like activity of PtCu NPs to specifically detect Fe²⁺ in a solution of an oral iron supplement and compared these results with data acquired from atomic absorption spectroscopy and the phenanthroline colorimetric method. The results showed that the newly developed PtCu NPs detection method was equivalent to or better than the other two methods used for Fe²⁺ detection. The antibacterial experiments showed that PtCu NPs have strong antibacterial activity against Staphylococcus aureus and Escherichia coli. Herein, we demonstrate that the peroxidase-like activity of PtCu NPs can catalyze H₂O₂ and generate hydroxyl radicals, which may elucidate the antibacterial activity of the PtCu NPs against S. aureus and E. coli. These results showed that PtCu NPs exhibited both ferroxidase- and peroxidase-like activity and that they may serve as convenient and efficient NPs for the detection of Fe²⁺ and for antibacterial applications.

Keywords:

• PtCu NPs
• ferroxidase-like activity
• Fe2+ detection
• peroxidase-like activity
• antibacterial activity

Acknowledgments

This paper is not an official US FDA guidance or policy statement. No official support or endorsement by the US FDA is intended or should be inferred.

Disclosure statement

The authors declare no competing financial interest.

Additional information

Funding

This work was also supported by the National Natural Science Foundation of China (Grant No. 31601447), the Program for Innovative Research Team (in Science and Technology) in University of Henan Provence (19IRTSTHN026), Key science and technology Project of Henan Science and Technology Department (182102110435). the grants from Henan Educational Administration (16A550005), and Xuchang Science and Technology project (20160213151). This work was also supported by a regulatory science grant under the FDA Nanotechnology CORES Program.