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Green synthesis of silver/montmorillonite/chitosan bionanocomposites using the UV irradiation method and evaluation of antibacterial activity.

Shameli K, Ahmad MB, Yunus WM, Rustaiyan A, Ibrahim NA, Zargar M, Abdollahi Y - Int J Nanomedicine (2010)

Bottom Line: Meanwhile, the crystalline structure and d-spacing of the MMT interlayer, average size and size distribution, surface morphology, elemental signal peaks, functional groups, and surface plasmon resonance of Ag/MMT/Cts BNCs were determined by powder X-ray diffraction, transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray fluorescence, Fourier transform infrared, and UV-visible spectroscopy.All of the synthesized Ag/MMT/Cts BNCs were found to have high antibacterial activity.These results show that Ag/MMT/Cts BNCs can be useful in different biologic research and biomedical applications, such as surgical devices and drug delivery vehicles.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, Universiti Putra Malaysia, Serdang, Selangor, Malaysia. kamyarshameli@gmail.com

ABSTRACT
In this study, silver nanoparticles (Ag-NPs) were synthesized using a green physical synthetic route into the lamellar space of montmorillonite (MMT)/chitosan (Cts) utilizing the ultraviolet (UV) irradiation reduction method in the absence of any reducing agent or heat treatment. Cts, MMT, and AgNO(3) were used as the natural polymeric stabilizer, solid support, and silver precursor, respectively. The properties of Ag/MMT/Cts bionanocomposites (BNCs) were studied as the function of UV irradiation times. UV irradiation disintegrated the Ag-NPs into smaller sizes until a relatively stable size and size distribution were achieved. Meanwhile, the crystalline structure and d-spacing of the MMT interlayer, average size and size distribution, surface morphology, elemental signal peaks, functional groups, and surface plasmon resonance of Ag/MMT/Cts BNCs were determined by powder X-ray diffraction, transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray fluorescence, Fourier transform infrared, and UV-visible spectroscopy. The antibacterial activity of Ag-NPs in MMT/Cts was investigated against Gram-positive bacteria, ie, Staphylococcus aureus and methicillin-resistant S. aureus and Gram-negative bacteria (ie, Escherichia coli) by the disk diffusion method on Muller-Hinton Agar at different sizes of Ag-NPs. All of the synthesized Ag/MMT/Cts BNCs were found to have high antibacterial activity. These results show that Ag/MMT/Cts BNCs can be useful in different biologic research and biomedical applications, such as surgical devices and drug delivery vehicles.

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Fourier transform infrared spectra for A) chitosan, B) montmorillonite/chitosan, and C) montmorillonite.
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f8-ijn-5-875: Fourier transform infrared spectra for A) chitosan, B) montmorillonite/chitosan, and C) montmorillonite.

Mentions: The mechanism of the Ag/MMT/Cts BNCs synthesized from AgNO3/MMT/Cts produced by UV irradiation reduction is depicted schematically in Figure 1. During UV irradiation, the reduction and fragmentation of large Ag-NPs happen simultaneously. The small sizes of Ag-NPs were intercalated into the lamellar space of MMT/Cts utilizing the UV irradiation reduction method in the absence of any chemical reducing agent or heat treatment. The color of the prepared samples at different UV irradiation times gradually changed from colorless for AgNO3/MMT/Cts to light gray, then to gray, and finally to dark gray, indicating the formation of Ag-NPs in the MMT/Cts suspension (Figure 2). The formation of Ag-NPs was also followed by measuring the surface plasmon resonance bands of AgNO3/MMT/Cts (A0) and Ag/MMT/Cts BNCs suspensions (A1–A5) at wavelengths in the 300–700 nm range (Figure 3). Comparison between the powder X-ray diffraction patterns of MMT, MMT/Cts, and Ag/MMT/Cts BNCs (A2, A4, and A5) in the small angle range of 2θ (2° < 2θ < 10°) indicated the formation of the intercalated Ag-NP structure (Figure 4). Powder X-ray diffraction patterns in the wide angle range of 2θ (30° < 2θ < 80°) were also employed to determine the crystalline structures of the synthesized Ag-NPs ( Figure 5). Transmission electron microscopy images and size distributions of the Ag-NPs showed the mean diameter of the nanoparticles, which were mostly in the 3.16–10.97 nm range (Figure 6). Scanning electron microscopy images indicated that there were structural changes between the initial MMT, MMT/Cts, and Ag/MMT/Cts BNCs under a longer UV irradiation time. Additionally, the energy dispersive X-ray fluorescence spectra for the MMT, MMT/Cts, and Ag/MMT/Cts BNCs (A5) confirmed the presence of elemental compounds in the MMT, Cts, and Ag-NPs without any other impurity peaks (Figure 7). The chemical structures of the MMT, MMT/Cts, and Ag/MMT/Cts BNCs were analyzed using Fourier transform infrared spectroscopy (Figures 8 and 9). The antibacterial studies showed comparable effects for all samples between MMT, AgNO3/MMT/Cts (A0), and Ag/MMT/Cts BNCs (A2, A4, and A5) against different bacteria as indicated by the inhibition zone test (Figure 10 and Table 1).


Green synthesis of silver/montmorillonite/chitosan bionanocomposites using the UV irradiation method and evaluation of antibacterial activity.

Shameli K, Ahmad MB, Yunus WM, Rustaiyan A, Ibrahim NA, Zargar M, Abdollahi Y - Int J Nanomedicine (2010)

Fourier transform infrared spectra for A) chitosan, B) montmorillonite/chitosan, and C) montmorillonite.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2990381&req=5

f8-ijn-5-875: Fourier transform infrared spectra for A) chitosan, B) montmorillonite/chitosan, and C) montmorillonite.
Mentions: The mechanism of the Ag/MMT/Cts BNCs synthesized from AgNO3/MMT/Cts produced by UV irradiation reduction is depicted schematically in Figure 1. During UV irradiation, the reduction and fragmentation of large Ag-NPs happen simultaneously. The small sizes of Ag-NPs were intercalated into the lamellar space of MMT/Cts utilizing the UV irradiation reduction method in the absence of any chemical reducing agent or heat treatment. The color of the prepared samples at different UV irradiation times gradually changed from colorless for AgNO3/MMT/Cts to light gray, then to gray, and finally to dark gray, indicating the formation of Ag-NPs in the MMT/Cts suspension (Figure 2). The formation of Ag-NPs was also followed by measuring the surface plasmon resonance bands of AgNO3/MMT/Cts (A0) and Ag/MMT/Cts BNCs suspensions (A1–A5) at wavelengths in the 300–700 nm range (Figure 3). Comparison between the powder X-ray diffraction patterns of MMT, MMT/Cts, and Ag/MMT/Cts BNCs (A2, A4, and A5) in the small angle range of 2θ (2° < 2θ < 10°) indicated the formation of the intercalated Ag-NP structure (Figure 4). Powder X-ray diffraction patterns in the wide angle range of 2θ (30° < 2θ < 80°) were also employed to determine the crystalline structures of the synthesized Ag-NPs ( Figure 5). Transmission electron microscopy images and size distributions of the Ag-NPs showed the mean diameter of the nanoparticles, which were mostly in the 3.16–10.97 nm range (Figure 6). Scanning electron microscopy images indicated that there were structural changes between the initial MMT, MMT/Cts, and Ag/MMT/Cts BNCs under a longer UV irradiation time. Additionally, the energy dispersive X-ray fluorescence spectra for the MMT, MMT/Cts, and Ag/MMT/Cts BNCs (A5) confirmed the presence of elemental compounds in the MMT, Cts, and Ag-NPs without any other impurity peaks (Figure 7). The chemical structures of the MMT, MMT/Cts, and Ag/MMT/Cts BNCs were analyzed using Fourier transform infrared spectroscopy (Figures 8 and 9). The antibacterial studies showed comparable effects for all samples between MMT, AgNO3/MMT/Cts (A0), and Ag/MMT/Cts BNCs (A2, A4, and A5) against different bacteria as indicated by the inhibition zone test (Figure 10 and Table 1).

Bottom Line: Meanwhile, the crystalline structure and d-spacing of the MMT interlayer, average size and size distribution, surface morphology, elemental signal peaks, functional groups, and surface plasmon resonance of Ag/MMT/Cts BNCs were determined by powder X-ray diffraction, transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray fluorescence, Fourier transform infrared, and UV-visible spectroscopy.All of the synthesized Ag/MMT/Cts BNCs were found to have high antibacterial activity.These results show that Ag/MMT/Cts BNCs can be useful in different biologic research and biomedical applications, such as surgical devices and drug delivery vehicles.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, Universiti Putra Malaysia, Serdang, Selangor, Malaysia. kamyarshameli@gmail.com

ABSTRACT
In this study, silver nanoparticles (Ag-NPs) were synthesized using a green physical synthetic route into the lamellar space of montmorillonite (MMT)/chitosan (Cts) utilizing the ultraviolet (UV) irradiation reduction method in the absence of any reducing agent or heat treatment. Cts, MMT, and AgNO(3) were used as the natural polymeric stabilizer, solid support, and silver precursor, respectively. The properties of Ag/MMT/Cts bionanocomposites (BNCs) were studied as the function of UV irradiation times. UV irradiation disintegrated the Ag-NPs into smaller sizes until a relatively stable size and size distribution were achieved. Meanwhile, the crystalline structure and d-spacing of the MMT interlayer, average size and size distribution, surface morphology, elemental signal peaks, functional groups, and surface plasmon resonance of Ag/MMT/Cts BNCs were determined by powder X-ray diffraction, transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray fluorescence, Fourier transform infrared, and UV-visible spectroscopy. The antibacterial activity of Ag-NPs in MMT/Cts was investigated against Gram-positive bacteria, ie, Staphylococcus aureus and methicillin-resistant S. aureus and Gram-negative bacteria (ie, Escherichia coli) by the disk diffusion method on Muller-Hinton Agar at different sizes of Ag-NPs. All of the synthesized Ag/MMT/Cts BNCs were found to have high antibacterial activity. These results show that Ag/MMT/Cts BNCs can be useful in different biologic research and biomedical applications, such as surgical devices and drug delivery vehicles.

Show MeSH
Related in: MedlinePlus