Deposition of Silver Nanoparticles on Dendrimer Functionalized Multiwalled Carbon Nanotubes: Synthesis, Characterization and Antimicrobial Activity

Neelgund, Gururaj M.; Oki, Aderemi

doi:10.1166/jnn.2011.3756

Cited by 64 publications

(56 citation statements)

References 26 publications

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“…1 Therefore, silver-based nanomaterials are being used for their bactericidal activity. 2,3 Although the antimicrobial activity of silver is well known, its mechanism of action is not yet fully understood. Several mechanisms have been proposed, such as a loss of the replication ability of DNA 4 and changes in membrane structure.…”

Section: Introductionmentioning

confidence: 99%

Silver-coated carbon nanotubes downregulate the expression of Pseudomonas aeruginosa virulence genes: a potential mechanism for their antimicrobial effect

Dosunmu¹,

Chaudhari²,

Singh³

et al. 2015

IJN

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The antimicrobial activity of silver-coated carbon nanotubes (AgCNTs) and their potential mode of action against mucoid and nonmucoid strains of Pseudomonas aeruginosa was investigated in vitro. The results showed that AgCNTs exhibited antimicrobial activity against both strains with minimum inhibitory concentrations of approximately 8 µg/mL, indicating a high sensitivity of P. aeruginosa to AgCNTs. AgCNTs were also bactericidal against both strains at the same minimum inhibitory concentration. Scanning and transmission electron-microscopy studies further revealed that a majority of the cells treated with AgCNTs transformed from smooth rod-shape morphology to disintegrated cells with broken/damaged membranes, resulting in leakage of cytoplasmic contents to produce ghost cells. The molecular effects of AgCNTs on P. aeruginosa genes involved in virulence and pathogenicity, stress response, and efflux pumps were evaluated for changes in their expression. Quantitative real-time PCR (qRT-PCR) showed that after exposure to AgCNTs, the expression levels of the rpoS , rsmZ , and oprD genes were significantly downregulated in both strains of P. aeruginosa compared to the untreated samples. These results suggest that the mechanism of action of AgCNTs may be attributed to their effect on cell-membrane integrity, downregulation of virulence-gene expression, and induction of general and oxidative stress in P. aeruginosa .

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Section: Introductionmentioning

confidence: 99%

Silver-coated carbon nanotubes downregulate the expression of Pseudomonas aeruginosa virulence genes: a potential mechanism for their antimicrobial effect

Dosunmu¹,

Chaudhari²,

Singh³

et al. 2015

IJN

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“…17 Silicon present in the sample may have originated from impurities included in TEM substrates or from artifacts during sample preparation. 17,21,22 In addition, structural validation of the Ag and carbon nanomaterials was assessed via examination of Ag-MWCNTs and MWCNTs-COOH XRD patterns, which indicate two major diffraction peaks at 2θ=26.1° and 42.6° in the (002) and (110) planes, respectively ( Figure 2E). The broad diffraction peak of the (002) plane can be correlated with the structural ordering of MWCNT, 23 while diffraction peaks observed at 2θ=38.08°, 44.3°, 64.46°, and 77.36° correlate to the (111), (200), (220), and (311) planes, respectively -all standard features for a face-centered cubic silver crystalline structure.…”

Section: Discussionmentioning

confidence: 99%

“…Recent studies evaluating the antibacterial potential of silver nanomaterials and silver-containing products have shown these to be particularly effective against Escherichia coli. 21,[24][25][26] In particular, Methylobacterium spp. and Sphingomonas spp.…”

Section: Discussionmentioning

confidence: 99%

Antibacterial activity and cytotoxicity of multi-walled carbon nanotubes decorated with silver nanoparticles

Seo¹,

Hwang²,

Kim³

et al. 2014

IJN

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Recently, various nanoscale materials, including silver (Ag) nanoparticles, have been actively studied for their capacity to effectively prevent bacterial growth. A critical challenge is to enhance the antibacterial properties of nanomaterials while maintaining their biocompatibility. The conjugation of multiple nanomaterials with different dimensions, such as spherical nanoparticles and high-aspect-ratio nanotubes, may increase the target-specific antibacterial capacity of the consequent nanostructure while retaining an optimal biocompatibility. In this study, multi-walled carbon nanotubes (MWCNTs) were treated with a mixture of acids and decorated with Ag nanoparticles via a chemical reduction of Ag cations by ethanol solution. The synthesized Ag-MWCNT complexes were characterized by transmission electron microscopy, X-ray diffractometry, and energy-dispersive X-ray spectroscopy. The antibacterial function of Ag-MWCNTs was evaluated against Methylobacterium spp. and Sphingomonas spp. In addition, the biocompatibility of Ag-MWCNTs was evaluated using both mouse liver hepatocytes (AML 12) and human peripheral blood mononuclear cells. Finally, we determined the minimum amount of Ag-MWCNTs required for a biocompatible yet effective antibacterial treatment modality. We report that 30 μg/mL of Ag-MWCNTs confers antibacterial functionality while maintaining minimal cytotoxicity toward both human and animal cells. The results reported herein would be beneficial for researchers interested in the efficient preparation of hybrid nanostructures and in determining the minimum amount of Ag-MWCNTs necessary to effectively hinder the growth of bacteria.

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“…6 γ-irradiation, 7 and other synthesis routes, [8][9][10][11][12][13][14] have been attempted to attach silver nanoparticles (NPs) or nanoclusters on the functionalized CNTs. To prepare well-constructed silver NP-decorated CNTs, however, a simple and effective route is still more desired.…”

mentioning

confidence: 99%

“…5 Hybrid systems of nanomaterials may have collective properties that are drastically different from a simple combination of individual components. Therefore, many approaches and strategies, including the solid-state reaction, 2 vaporizing deposition, 3 surface chemical reduction, 4 electrochemical deposition, 6 γ-irradiation, 7 and other synthesis routes, [8][9][10][11][12][13][14] have been attempted to attach silver nanoparticles (NPs) or nanoclusters on the functionalized CNTs. To prepare well-constructed silver NP-decorated CNTs, however, a simple and effective route is still more desired.…”

mentioning

confidence: 99%

In Situ Synthesis of Highly Dispersed Silver Nanoparticles on Multiwalled Carbon

Hou¹,

Wang²,

Ren-tao³

2011

Bulletin of the Korean Chemical Society

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Since their discovery, 1 carbon nanotubes (CNTs) have been continuously attracting extensive interests in many areas of science and technology and have been the focus of current research for many years due to their unique structure-dependent optical, electrical, and mechanical properties. Recently, silver decorated CNT hybrids are increasingly attracting extensive attention due to their potential applications as catalyst, 2 broad-band optical limiters, 3 electrodes, 4 and advanced materials.5 Hybrid systems of nanomaterials may have collective properties that are drastically different from a simple combination of individual components. Therefore, many approaches and strategies, including the solid-state reaction,6 γ-irradiation, 7 and other synthesis routes, [8][9][10][11][12][13][14] have been attempted to attach silver nanoparticles (NPs) or nanoclusters on the functionalized CNTs. To prepare well-constructed silver NP-decorated CNTs, however, a simple and effective route is still more desired.Here we report on a novel and facile wet-chemical method for the synthesis of silver NP-CNT assemblies, that is based on traditional coordination chemistry and can be generally applied to common metal elements. Key to the synthesis lies in the 3-aminopropyltriethoxysilane (APS)-mediated loading of silver precusors on the functionalized CNTs. The full procedure for preparing silver NP-CNT composites is shown in Figure 1.MWCNTs were obtained from NTP (Shenzhen, China). Lithium aluminum hydride (LiAlH 4 , 95%) and APS (99%) were purchased from Aldrich. Other chemicals used were all analytical pure and purchased from Sinopharm Chemical Reagent Co. Ltd. (Shanghai, China). Surface treatment of MWCNTs followed a standard route. In brief, MWCNTs were reuxed in mixture acids made of nitric acid and sulfuric acid for 2 h to give carboxyl groups modified MWCNT (MWCNT-COOH), 15 followed by reaction with LiAlH 4 in dry tetrahydrofuran (THF) at room temperature for 12 h, resulting in hydroxyl group functionalized MWCNT (MWCNT-OH). The (MWCNT-O-) 3 -Si(CH 2 ) 3 NH 2 intermediate was realized via covalent coupling of MWCNT-OH and an excess of APS in anhydrous toluene at 120 o C for 24 h under the protection of argon (Ar). The (MWCNT-O-) 3 Si(CH 2 ) 3 NH 2 -Ag + complex was obtained by reaction between (MWCNT-O-) 3 Si(CH 2 ) 3 NH 2 and 1.0 mol/L AgNO 3 solution at room temperature for 2 h. The final silver NP loaded MWCNT (MWCNT-O-) 3 Si(CH 2 ) 3 -NH 2 Ag) hybrids were fabricated via in situ reduction with sodium borohydride (NaBH 4 ). The as-prepared mixtures were fully washed with distilled water and absolute ethanol for several times. Finally, the products were collected by centrifugation and the precipitate was dried at 60 o C in vacuum for 10 h.The morphology and dimension of the product were observed by transmission electron microscopy (TEM), which was taken on a Hitachi Model H-600 electron microscopy using an accelerating voltage of 100 kV. The crystalline structure of the sample was characterized by X-ray diffractometer equipped...

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Deposition of Silver Nanoparticles on Dendrimer Functionalized Multiwalled Carbon Nanotubes: Synthesis, Characterization and Antimicrobial Activity

Cited by 64 publications

References 26 publications

Silver-coated carbon nanotubes downregulate the expression of Pseudomonas aeruginosa virulence genes: a potential mechanism for their antimicrobial effect

Silver-coated carbon nanotubes downregulate the expression of Pseudomonas aeruginosa virulence genes: a potential mechanism for their antimicrobial effect

Antibacterial activity and cytotoxicity of multi-walled carbon nanotubes decorated with silver nanoparticles

In Situ Synthesis of Highly Dispersed Silver Nanoparticles on Multiwalled Carbon

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