Preparation and Antibiofilm Properties of Zinc Oxide/Porous Anodic Alumina Composite Films

Shuying Xu,Qiushi Song,Changping Duan,Tong Sun,Lili Wang,Qian Xu,Yue Dai

doi:10.1186/s11671-018-2568-4

Abstract

The PAA (porous anodic alumina) films were prepared by two-step anodic oxidation after different times, and then the ZnO/PAA composite films were prepared by sol-gel method on their surface. Meanwhile, the ZnO/PAA composite films were characterized by X-ray diffraction (XRD), thermogravimetric/differential thermal analyzer (TG/DTA), Fourier transform infrared spectrometer (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and water contact angle (CA). The antibiofilm properties of ZnO/PAA composite films on Shewanella putrefaciens were measured simultaneously. The results show that the micromorphologies of PAA and ZnO/PAA composite films are affected by second anodization time. ZnO is a hexagonal wurtzite structure, and ZnO particles with a diameter of 10–30 nm attach to the inner or outer surfaces of PAA. After being modified by Si69, the ZnO films translate from hydrophilia to hydrophobicity. The ZnO/PAA film with the optimal antibiofilm properties is prepared on the PAA surface by two-step anodization for 40 min. The adherence of Shewanella putrefaciens is restrained by its super-hydrophobicity, and the growth of biofilm bacteria is inhibited by its abundant ZnO particles.

Highlights

As we know, the bacteria can adhere to solid surfaces and form a slippery biofilm in appropriate environments [1]
Characterization of ZnO Films X-ray diffraction (XRD) Characterization of the ZnO Powders Prepared by Solgel Process The antibacterial and antibiofilm properties of zinc oxide are affected by its crystal structure [33, 34]
Biofilm on ZnO/porous anodic alumina (PAA) Composite Films The ZnO/PAA composite films with biofilm were washed three times with sterile phosphate-buffered saline (PBS, pH 7.4; 137 mmol/L NaCl, 2.7 mmol/L KCl, 10 mmol/L Na2HPO4, and 1.8 mmol/L KH2PO4) to dislodge floating bacteria, and the stained biofilms were ultrasonically stripped in 10-mL sterile Phosphate-buffered saline (PBS) at 53 KHz, 280 W for 10 min

Summary

Introduction

The bacteria can adhere to solid surfaces and form a slippery biofilm in appropriate environments [1]. The bacteria biofilms stick firmly to the surfaces of materials, such as stainless steel [2], rubber [3], glass [4], and polystyrene [5]. Bohinc et al [10] pointed out that the bacterial adherence would increase with the surface roughness of the glass. Singh et al [12] demonstrated that high surface roughness can improve protein adsorption and accelerate the bacterial adhesion and Aluminum materials have been widely used, and porous anodic alumina (PAA) has drawn more attention in the fields of light electrical function, catalytic function, and sensing function in recent years [21,22,23,24], and its antimicrobial activity was reported. Ferraz et al [24] reported that PAA can induce the adhering activation of monocytes/ macrophages due to their matrix phase and nanoporosity

Methods

Results

Conclusion