Palygorskite-Based Organic–Inorganic Hybrid Nanocomposite for Enhanced Antibacterial Activities

Aiping Hui,Fangfang Yang,Aiqin Wang,Yuru Kang,Rui Yan

doi:10.3390/nano11123230

Aiping Hui, Fangfang Yang + Show 3 more

Open Access

https://doi.org/10.3390/nano11123230

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Abstract

A synergistic antibacterial strategy is effective in enhancing the antibacterial efficacy of a single antibacterial material. Plant essential oils (PEOs) are safe antibacterial agents. However, some of their characteristics such as intense aroma, volatility, and poor thermal stability limit their antibacterial activity and applications. In this paper, five kinds of PEOs were incorporated onto ZnO/palygorskite (ZnO/PAL) nanoparticles by a simple adsorption process to form organic–inorganic nanocomposites (PEOs/ZnO/PAL) with excellent antibacterial properties. TEM and SEM analyses demonstrated that ZnO nanoparticles uniformly anchored onto the surface of rod-like PAL, and that the structure of ZnO/PAL maintained after the incorporation of ZnO nanoparticles and PEOs. It was found that carvacrol/ZnO/palygorskite (CAR/ZnO/PAL) exhibited higher antibacterial activities than other PEOs/ZnO/PAL nanocomposites, with minimum inhibitory concentration (MIC) values of 0.5 mg/mL and 1.5 mg/mL against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), respectively. Moreover, the antibacterial efficiency of CAR/ZnO/PAL nanocomposites was superior to that of ZnO/PAL and pure CAR, demonstrating the synergistic effect that occurs in the combined system. PAL serving as a carrier for the combination of organic PEOs and ZnO nanoparticles is an effective strategy for enhanced, clay-based, organic–inorganic hybrid antibacterial nanocomposites.

Highlights

Plant essential oils (PEOs) and their extracts have been examined for their effectiveness in food preservation [1,2,3,4,5]
It was found that carvacrol/ZnO/palygorskite (CAR/ZnO/PAL) exhibited higher antibacterial activities than other PEOs/ZnO/PAL nanocomposites, with minimum inhibitory concentration (MIC) values of 0.5 mg/mL and 1.5 mg/mL against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), respectively
In these PEOs/ZnO/PAL composites, PEOs play a vital role in enhancing the antibacterial activities of inorganic ZnO/PAL

Summary

Introduction

Plant essential oils (PEOs) and their extracts have been examined for their effectiveness in food preservation [1,2,3,4,5]. PEOs as naturally occurring, biologically active agents have been shown to possess anti-inflammatory, antioxidant, antibacterial, and antifungal properties [6,7,8]. There has been a growing demand for natural PEOs in antibacterial applications owing to their safety and extensive sources such as plant leaves, barks, stems, roots, flowers, and fruits [9,10,11,12,13]. PEOs suffer from the problems of volatility, tangy aromatic odor, and poor thermal stability, which would diminish their antibacterial activity as well as limit their practical applications [17,18]. It is known that the complexes of various antibacterial components could obtain synergistic antibacterial effects, making it a feasible route for utilizing the advantages of various antibacterial factors

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Conclusion