Synthesis and Characterization of TiO2-ZnO-MgO Mixed Oxide and Their Antibacterial Activity

Abstract

TiO2-ZnO-MgO mixed oxide nanomaterials (MONs) were synthetized via the sol-gel method and characterized by scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), nitrogen physisorption analysis, X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS), Fourier transform infrared spectroscopy (FTIR), and color (Luminosity (L), a, b, Chrome, hue) parameters. Furthermore, the antimicrobial activity of the MONs was tested against Escherichia coli (EC), Salmonella paratyphi (SP), Staphylococcus aureus (SA), and Listeria monocytogenes (LM). The MONs presented a semi globular-ovoid shape of ≤100 nm. Samples were classified as mesoporous materials and preserved in the TiO2 anatase phase, with slight changes in the color parameters of the MONs in comparison with pure TiO2. The MONs exhibited antimicrobial activity, and their effect on the tested bacteria was in the following order: EC > SP > SA > LM. Therefore, MONs could be used as antimicrobial agents for industrial applications.

Chitosan-TiO2: A Versatile Hybrid Composite

“…Figure 2a shows a typical FTIR spectra of a CS-TiO2 hybrid composite (consistent with reported FTIR spectra in literature for CS-TiO2 composites [16,40,48]), where the most representative FTIR band positions of the chitosan-TiO2 hybrid composite are listed in Table 3. Fourier transform infrared spectra of TiO2, chitosan, and chitosan-TiO2 hybrid composite (a) (the CS-TiO2 composite was prepared in our laboratory following the methodology of Siripatrawan and Kaewklin [40] by using 1 g chitosan with medium molecular weight (Sigma-Aldrich, St. Louis, MO, USA) dissolved in 1% acetic acid solution, the nano-TiO2 (previously characterized in reference [14]) was 1% of the total chitosan weight, and 15% of glycerol weight of the total solids), and schematic representation of CS-TiO2 hybrid composite structure (b).…”

“…Fourier transform infrared spectra of TiO 2 , chitosan, and chitosan-TiO 2 hybrid composite (a) (the CS-TiO 2 composite was prepared in our laboratory following the methodology of Siripatrawan and Kaewklin [40] by using 1 g chitosan with medium molecular weight (Sigma-Aldrich, St. Louis, MO, USA) dissolved in 1% acetic acid solution, the nano-TiO 2 (previously characterized in reference [14]) was 1% of the total chitosan weight, and 15% of glycerol weight of the total solids), and schematic representation of CS-TiO 2 hybrid composite structure (b). [42,50,69] According to Siripatrawan and Kaewklin [40], the incorporation of TiO 2 into the chitosan matrix mainly occurs in the amorphous region of chitosan, strengthening the hydrogen bond (3300 cm −1 ) in the CS-TiO 2 complex [69,71] (Figure 2a).…”

“…Furthermore, the antimicrobial activity of CS-TiO 2 composites could be enhanced by the modification of the TiO 2 band gap associated with the presence of other compounds in the TiO 2 matrix [14]. Raut et al [10] informed that the incorporation of TiO 2 :Cu-doped nanoparticles (1 mg mL −1 ) into CS matrix (CS-TiO 2 :Cu) increased up to 200% the photocatalytic antimicrobial activity of CS-TiO 2 composite against E. coli and S. aureus.…”

“…The wide use of TiO 2 is supported by its physicochemical, mechanical, and photocatalytic properties; reactivity and thermal stability; and low cost, safe production, and biocompatibility [13]. TiO 2 can be doped with other inorganic compounds (mainly metallic compounds) to enhance the interfacial charge transfer and restricts the electron-hole recombination, which improve the photocatalytic properties of TiO 2 under visible light [14]; however, one of the major disadvantages of nano-TiO 2 is its ability to agglomerate. It has been reported that the interaction between nano-TiO 2 and biopolymers (starch, gums, and chitosan) can help to reduce the spontaneous agglomeration of the TiO 2 , thus enhancing the functional properties of composite [15].In the last decade, a strong interest has emerged in hybrid composites and their potential uses, especially in the CS-TiO 2 composites, which exhibit interesting properties mainly by their combined and additive characters of organic and inorganic materials [1,6].…”

<p>Comparative Study of Antibacterial Effects of Titanium Dioxide Nanoparticles Alone and in Combination with Antibiotics on MDR <em>Pseudomonas aeruginosa</em> Strains</p>

“…Many nanoparticle shapes with nonuniform size and superficial agglomeration were reported for TiO 2 , which appeared to be a normal reaction during the sol-gel method synthesis. 18,19 Diffraction Scanning Calorimetry Studies DSC is a significant tool to predict the physicochemical changes associated with drug interactions of the tested antibacterial agents and TDN. Drug interactions may be detected through shifts in peaks onset, area, or even disappearance of peaks.…”