Antimicrobial activity and synergistic antibacterial mechanism of a combination of zinc and rare-earth scandium against Escherichia coli

ABSTRACT

In this study, rare-earth elements Sc and Zn were deposited on an advanced functional antimicrobial amorphous silica composite (ASC) using the sol–gel method at room temperature. The optimal preparation conditions were determined to achieve the maximum antibacterial activity by evaluating single factors. The optimal Zn²⁺ and Sc³⁺ concentrations were found to be 0.9 mol·L^–1 and 3 mmol·L^–1, respectively. The results show that the Zn-Sc ASC is amorphous and porous. ICP analysis indicated 1.81% Zn and 0.058% Sc (wt%). The antibacterial activity of Zn ASC after adding rare-earth element Sc increased from 65% to 90%. The synergistic antibacterial effect between Sc and Zn ASC can be attributed to the increased specific surface area of Zn ASC owing to the addition of Sc and the enhanced loading of Zn²⁺ on ASC producing more reactive oxygen species (ROS).

KEYWORDS:

• Sol–gel method
• Zn-Sc ASC
• antimicrobial activity
• synergistic effect

Acknowledgments

I am profoundly grateful to my supervisor, Huaming Mao, whose illuminating instruction helped me to clarify my ideas. Especially thanks to Yibo Shi for contributing some experiments to this paper. I thank the National Key R&D Program of China (Grant No. 2017YFC0210303, China) for financial support.

Disclosure statement

No potential conflict of interest was reported by the authors.

Declaration

The authors declare no conflict of interest when submitting this manuscript; all the authors have approved the publication of this manuscript.

Additional information

Funding

This work was supported by the National Key R&D Program of China [2017YFC0210303].