Preparation and antibacterial behaviour of nanostructured Ag@SiO<sub>2</sub>–penicillin with silver nanoplates

Malekzadeh, Mercedeh; Yeung, King Lun; Halali, Mohammad; Chang, Qing

doi:10.1039/c9nj03727f

Cited by 11 publications

(14 citation statements)

References 54 publications

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“…The wide and strong broad band with the maximum located at 1100 cm −1 is typical for asymmetric stretching vibrations of the Si–O-Si group. The absorption band at 950 cm −1 can be ascribed to the bending vibration of Si-OH group, but the peak at 800 cm −1 can be associated with the Si–O–Si symmetric stretching vibrations [ 46 , 47 ]. We also propose that the peak at 470 cm −1 corresponds to the bending of the bridging oxygen atom perpendicular to the Si-O-Si plane.…”

Section: Resultsmentioning

confidence: 99%

Dansyl-Labelled Ag@SiO2 Core-Shell Nanostructures—Synthesis, Characterization, and Metal-Enhanced Fluorescence

et al. 2020

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The present work describes synthesis, characterization, and use of a new dansyl-labelled Ag@SiO2 nanocomposite as an element of a new plasmonic platform to enhance the fluorescence intensity. Keeping in mind that typical surface plasmon resonance (SPR) characteristics of silver nanoparticles coincide well enough with the absorption of dansyl molecules, we used them to build the core of the nanocomposite. Moreover, we utilized 10 nm amino-functionalized silica shell as a separator between silver nanoparticles and the dansyl dye to prevent the dye-to-metal energy transfer. The dansyl group was incorporated into Ag@SiO2 core-shell nanostructures by the reaction of aminopropyltrimethoxysilane with dansyl chloride and we characterized the new dansyl-labelled Ag@SiO2 nanocomposite using transmission electron microscopy (TEM) and Fourier-transform infrared spectroscopy (FTIR). Additionally, water wettability measurements (WWM) were carried out to assess the hydrophobicity and hydrophilicity of the studied surface. We found that the nanocomposite deposited on a semitransparent silver mirror strongly increased the fluorescence intensity of dansyl dye (about 87-fold) compared with the control sample on the glass, proving that the system is a perfect candidate for a sensitive plasmonic platform.

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Section: Resultsmentioning

confidence: 99%

Dansyl-Labelled Ag@SiO2 Core-Shell Nanostructures—Synthesis, Characterization, and Metal-Enhanced Fluorescence

et al. 2020

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“…191 Besides providing sufficient colloidal stability, the priming species also acts to increase the affinity of the nanoplate surface for silica. 189 Examples of priming agents implemented for surface passivation include (3-aminopropyl)trimethoxysilane, 192 (3-aminopropyl)triethoxysilane, 189 (3mercaptopropyl)trimethoxysilane, 189 (3-mercaptopropyl)triethoxysilane, 189 1,3diaminopropane, 189 16-mercaptohexadecanoic acid 191,193 and polyvinylpyrrolidone. 194 Upon adsorption of a primer species, silica shell growth can then commence through the DMA-catalyzed Stöber approach with TEOS.…”

Section: Fabrication and Photoactivation Of A 'Uni-nanomolecular' Hyb...mentioning

confidence: 99%

“…194 Upon adsorption of a primer species, silica shell growth can then commence through the DMA-catalyzed Stöber approach with TEOS. 189,191,193 Alternatively, silica shells can be deposited atop of primed silver nanoplates using an aqueous solution of sodium silicate. 189,192 Construction of silica shells using sodium silicate offers a desirable advantage, that being that the resultant shells are much thinner (on the order of a few nanometers, ranging from approximately 2-5 nm depending on other conditions such as silicate concentration and reaction time), in comparison to shells produced via the TEOS-based Stöber method.…”

Section: Fabrication and Photoactivation Of A 'Uni-nanomolecular' Hyb...mentioning

confidence: 99%

A Comprehensive Investigation Into How Metal Nanoparticles Enhance Photochemical Processes

Dogantzis

2024

Preprint

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<p>Integrated nanoparticle-fluorophore systems are an emerging class of hybrid materials with potential for a variety of applications. Within these systems, Metal-Enhanced Fluorescence (MEF) is a phenomenon that arises through the unique near-field interactions between organic fluorophores and metallic nanoparticles. These interactions can enhance fluorophore brightness by operating under two mechanistic pathways: increased fluorophore excitation, and increased fluorophore emission. It is critical, however, to garner an understanding of the balance between the two mechanisms in order to optimize its use for customized applications. In this work, silver nanoplates (AgNP) were synergistically integrated with a photoactivatable system consisting of a fluorogenic boron dipyrromethene (BODIPY) and select photoacid generators (PAGs). Light irradiation of the PAGs promotes the release of acid, which encourages the formation of a fluorescent BODIPY analogue. AgNP were found to enhance the output of steady-state emission via MEF. Furthermore, single molecule total internal reflection fluorescence microscopy (TIRFM) was executed to distinguish the relative contributions of the two MEF mechanisms between the quenched and fluorescent BODIPY fluorochromes and AgNP. Interestingly, increased excitation was the dominant MEF mechanism amongst both dyes. Finally, the rational design of a ‘uninanomolecular’ superstructure incorporating both a photoactivatable dihydrofluorescein dye and AgNP within a single system was investigated. Two synthetic approaches were proposed, however neither method yielded superstructures that photoactivated with subsequent MEF. Overall, this work aids to advance the understanding of complex particle-molecule interactions.</p>

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“…Furthermore, releasing active Ag + ions from the SiO 2 carrier as an effective antibacterial agent would explain their highly toxic effects on tested microorganisms [ 81 ]. It also suggests that depositing or capping Ag NPs in core-shell systems increases their toxicity, enabling their stabilization and preventing the direct formation of Ag-NP aggregates [ 94 ]. These findings also follow Ahmed et al [ 95 ], who observed a significant toxicological impact of Ag NPs obtained through microwave-mediated synthesis against E. coli , P. aeruginosa , S. aureus, and K. pneumoniae .…”

Section: Biological Studiesmentioning

confidence: 99%

Microwave Irradiation vs. Structural, Physicochemical, and Biological Features of Porous Environmentally Active Silver–Silica Nanocomposites

Strach

Dulski²,

Wasilkowski

et al. 2023

IJMS

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Heavy metals and other organic pollutants burden the environment, and their removal or neutralization is still inadequate. The great potential for development in this area includes porous, spherical silica nanostructures with a well-developed active surface and open porosity. In this context, we modified the surface of silica spheres using a microwave field (variable power and exposure time) to increase the metal uptake potential and build stable bioactive Ag2O/Ag2CO3 heterojunctions. The results showed that the power of the microwave field (P = 150 or 700 W) had a more negligible effect on carrier modification than time (t = 60 or 150 s). The surface-activated and silver-loaded silica carrier features like morphology, structure, and chemical composition correlate with microbial and antioxidant enzyme activity. We demonstrated that the increased sphericity of silver nanoparticles enormously increased toxicity against E. coli, B. cereus, and S. epidermidis. Furthermore, such structures negatively affected the antioxidant defense system of E. coli, B. cereus, and S. epidermidis through the induction of oxidative stress, leading to cell death. The most robust effects were found for nanocomposites in which the carrier was treated for an extended period in a microwave field.

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Preparation and antibacterial behaviour of nanostructured Ag@SiO₂–penicillin with silver nanoplates

Abstract: Preparation of Ag@SiO2–penicillin NPs with superior synergistic and antibacterial properties against methicillin-resistant Staphylococcus aureus.

Cited by 11 publications

References 54 publications

Dansyl-Labelled Ag@SiO2 Core-Shell Nanostructures—Synthesis, Characterization, and Metal-Enhanced Fluorescence

Dansyl-Labelled Ag@SiO2 Core-Shell Nanostructures—Synthesis, Characterization, and Metal-Enhanced Fluorescence

A Comprehensive Investigation Into How Metal Nanoparticles Enhance Photochemical Processes

Microwave Irradiation vs. Structural, Physicochemical, and Biological Features of Porous Environmentally Active Silver–Silica Nanocomposites

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Preparation and antibacterial behaviour of nanostructured Ag@SiO2–penicillin with silver nanoplates

Abstract: Preparation of Ag@SiO2–penicillin NPs with superior synergistic and antibacterial properties against methicillin-resistant Staphylococcus aureus.

Cited by 11 publications

References 54 publications

Dansyl-Labelled Ag@SiO2 Core-Shell Nanostructures—Synthesis, Characterization, and Metal-Enhanced Fluorescence

Dansyl-Labelled Ag@SiO2 Core-Shell Nanostructures—Synthesis, Characterization, and Metal-Enhanced Fluorescence

A Comprehensive Investigation Into How Metal Nanoparticles Enhance Photochemical Processes

Microwave Irradiation vs. Structural, Physicochemical, and Biological Features of Porous Environmentally Active Silver–Silica Nanocomposites

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Preparation and antibacterial behaviour of nanostructured Ag@SiO₂–penicillin with silver nanoplates