pH effect on the aggregation of silver nanoparticles synthesized by chemical reduction

ABSTRACT This paper reports citrate-stabilized silver nanoparticles (AgNPs) synthesized by nitrate ion chemical reduction with sodium borohydride, at different pHs (2–9). The AgNPs synthesized by this method exhibited size distribution from 5 to 249 nm, depending on pH, as determined by dynamic light scattering, and morphology spherical, as determined by transmission electron microscopy. In pH range 3–7 occurred aggregation of the nanoparticles. The size distribution depending on pH was determined by dynamic light scattering. The zeta potential was determined, and the colloidal stability was correlated with nanoparticles aggregation at different pHs. The size-dependent antimicrobial activity was evaluated for two solutions, wherein both samples exhibited antimicrobial activity, although the smallest AgNPs without agglomeration have enhanced antimicrobial properties.

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Antimicrobial Activity of Silver Nanoparticles Prepared Under an Ultrasonic Field

International Journal of Pharmaceutical Sciences and Nanotechnology ◽

10.37285/ijpsn.2011.4.3.8 ◽

2011 ◽

Vol 4 (3) ◽

pp. 1491-1496

Author(s):

Umadevi M ◽

Rani T ◽

Balakrishnan T ◽

Ramanibai R

Keyword(s):

Escherichia Coli ◽

Antimicrobial Activity ◽

Silver Nanoparticles ◽

Reduction Method ◽

Therapeutic Potential ◽

Chemical Reduction ◽

Ultrasonic Field ◽

Great Promise ◽

Chemical Reduction Method ◽

E Coli

Nanotechnology has great promise for improving the therapeutic potential of medicinal molecules and related agents. In this study, silver nanoparticles of different sizes were synthesized in an ultrasonic field using the chemical reduction method with sodium borohydride as a reducing agent. The size effect of silver nanoparticles on antimicrobial activity were tested against the microorganisms Staphylococcus aureus (MTCC No. 96), Bacillus subtilis (MTCC No. 441), Streptococcus mutans (MTCC No. 497), Escherichia coli (MTCC No. 739) and Pseudomonas aeruginosa (MTCC No. 1934). The results shows that B. subtilis, and E. coli were more sensitive to silver nanoparticles and its size, indicating the superior antimicrobial efficacy of silver nanoparticles.

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Size Control of Synthesized Silver Nanoparticles by Simultaneous Chemical Reduction and Laser Fragmentation in Origanum majorana Extract: Antibacterial Application

Materials ◽

10.3390/ma14092326 ◽

2021 ◽

Vol 14 (9) ◽

pp. 2326

Author(s):

Entesar Ali Ganash ◽

Reem Mohammad Altuwirqi

Keyword(s):

Silver Nanoparticles ◽

Irradiation Time ◽

Chemical Reduction ◽

Size Control ◽

Reduction Process ◽

Laser Wavelength ◽

X Ray Diffraction ◽

Ag Nps ◽

Transmission Electron ◽

Origanum Majorana

In this work, silver nanoparticles (Ag NPs) were synthesized using a chemical reduction approach and a pulsed laser fragmentation in liquid (PLFL) technique, simultaneously. A laser wavelength of 532 nm was focused on the as produced Ag NPs, suspended in an Origanum majorana extract solution, with the aim of controlling their size. The effect of liquid medium concentration and irradiation time on the properties of the fabricated NPs was studied. While the X-ray diffraction (XRD) pattern confirmed the existence of Ag NPs, the UV–Vis spectrophotometry showed a significant absorption peak at about 420 nm, which is attributed to the characteristic surface plasmon resonance (SPR) peak of the obtained Ag NPs. By increasing the irradiation time and the Origanum majora extract concentration, the SPR peak shifted toward a shorter wavelength. This shift indicates a reduction in the NPs’ size. The effect of PLFL on size reduction was clearly revealed from the transmission electron microscopy images. The PLFL technique, depending on experimental parameters, reduced the size of the obtained Ag NPs to less than 10 nm. The mean zeta potential of the fabricated Ag NPs was found to be greater than −30 mV, signifying their stability. The Ag NPs were also found to effectively inhibit bacterial activity. The PLFL technique has proved to be a powerful method for controlling the size of NPs when it is simultaneously associated with a chemical reduction process.

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Using a non-reducing sugar in the green synthesis of gold and silver nanoparticles by the chemical reduction method

DYNA ◽

10.15446/dyna.v85n206.72136 ◽

2018 ◽

Vol 85 (206) ◽

pp. 69-78 ◽

Cited By ~ 2

Author(s):

Wilson Agudelo ◽

Yuliet Montoya ◽

John Bustamante

Keyword(s):

Silver Nanoparticles ◽

Green Synthesis ◽

Reduction Method ◽

Chemical Reduction ◽

Reducing Sugar ◽

Chemical Reduction Method ◽

Gold And Silver Nanoparticles ◽

Uv Visible

El uso de compuestos químicos más biocompatibles y renovables para la obtención de nanopartículas metálicas con propiedades y características deseadas, se convierte en una ruta alternativa para la reducción de riesgos ambientales y del grado de incompatibilidad de estas estructuras al interactuar con modelos biológicos para su posible aplicación en el área de la salud. El propósito de este trabajo se centró en el uso de sacarosa, como agente reductor de nanopartículas de oro y plata al emplear diferentes volúmenes de hidróxido de sodio. Las nanopartículas obtenidas fueron caracterizadas mediante espectrometría UV-visible, microscopía electrónica de transmisión TEM y espectroscopia infrarroja por transformada de Fourier FTIR, la cual permitió determinar los plasmones de resonancia superficial, tamaños de partícula experimentales y teóricos, morfología y cambios estructurales en el agente reductor, así como la influencia del hidróxido de sodio en el proceso de síntesis. Los resultados obtenidos confirman la formación de nanopartículas de oro y plata mediante la previa formación de azúcares reductores. Así mismo, la oxidación del grupo funcional de la glucosa a sales de ácido carboxílico.

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Significant Parameters in the Optimization of Synthesis of Silver Nanoparticles by Chemical Reduction Method

Journal of Materials Engineering and Performance ◽

10.1007/s11665-009-9486-7 ◽

2009 ◽

Vol 19 (2) ◽

pp. 252-256 ◽

Cited By ~ 12

Author(s):

Zhihua Li ◽

Yanwei Wang ◽

Qianqian Yu

Keyword(s):

Silver Nanoparticles ◽

Reduction Method ◽

Chemical Reduction ◽

Chemical Reduction Method

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Antimicrobial and Cytotoxic Activity of Silver Nanoparticles Stabilized by Natural Biopolymer Arabinogalactan

International Journal of Nanoscience ◽

10.1142/s0219581x19500297 ◽

2020 ◽

Vol 19 (04) ◽

pp. 1950029

Author(s):

A. G. Demchenko ◽

V. S. Sadykova ◽

A. V. Lyundup ◽

N. E. Sedyakina ◽

T. I. Gromovykh ◽

...

Keyword(s):

Silver Nanoparticles ◽

Antifungal Activity ◽

Cytotoxic Activity ◽

Chemical Reduction ◽

Antitumor Agent ◽

Escherichia Coli Bacteria ◽

Trichoderma Citrinoviride ◽

Average Size ◽

Antibacterial And Antifungal ◽

Dose Dependent

Silver nanoparticles were synthesized by chemical reduction of silver nitrate using arabinogalactan polysaccharide as a reducing agent and a stabilizer. The average size of nanoparticles, obtained by analyzing TEM-images, was 10.8[Formula: see text]nm; zeta potential [Formula: see text][Formula: see text]mV. A study of the sol by electron diffraction showed that silver in the sample is in metallic form. The resulting preparation of silver nanoparticles showed both antibacterial and antifungal activity. A pronounced antibacterial activity of silver nanoparticles was demonstrated both in relation to conditionally pathogenic gram-positive (Bacillus subtilis and B. coagulans) and gram-negative (Escherichia coli) bacteria. Silver nanoparticles also possess antifungal activity against macromycete Fomitopsis sp., as well as two strains of micromycetes Trichoderma citrinoviride and Fusarium sporotrichioides. Using the methods of light and fluorescence microscopy, MTT-analysis and Real-time cell analysis, the cytotoxic activity of silver nanoparticles was investigated on HepG2 human hepatocellular carcinoma cells. It was demonstrated that nanoparticles cause a suppression of cell metabolic and proliferative activity, as well as dose-dependent induction of cell death (average relative EC[Formula: see text] value was [Formula: see text]g/ml). The preparation of silver nanoparticles stabilized by arabinogalactan can be used in medicine, as a potential antimicrobial and antitumor agent.

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Facile Synthesis of Silver Nanoparticles by Chemical Reduction Route

Materials Science Forum ◽

10.4028/www.scientific.net/msf.756.99 ◽

2013 ◽

Vol 756 ◽

pp. 99-105

Author(s):

Rajasingam Ratnamalar ◽

Mustapha Mariatti ◽

Zulkifli Ahmad ◽

Sharif Zein Sharif Hussein

Keyword(s):

Silver Nanoparticles ◽

Ag Nanoparticles ◽

Chemical Reduction ◽

Facile Synthesis ◽

Cubic Lattice ◽

Vis Spectroscopy ◽

Simple Chemical ◽

The Face ◽

Fine Control ◽

Xrd Patterns

This work reports a simple chemical reduction route for the preparation of uniformed Ag nanoparticles whereby a fine control over the sizes of the Ag nanoparticles was studied by varying the concentrations of the reducing agents used. In characterization, UV-Vis spectroscopy showed the changes in optical properties of the Ag nanoparticles with regards to their sizes, where as the XRD patterns of the synthesized Ag nanoparticles confirmed the distinct peaks approximately at 2θ = 38.1°, 44.3°, 64.4°, 77.4°, and 81.5 representing Bragg’s reflections from (111), (200), (220), (311), and (222) planes of the face centred cubic lattice phase. This route of synthesis is feasible to produce Ag nanoparticles with diameters in the range of 30-45 nm.

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Facile Synthesis of Silver Nanoparticles and Preparation of Conductive Ink

Nanomaterials ◽

10.3390/nano12010171 ◽

2022 ◽

Vol 12 (1) ◽

pp. 171

Author(s):

Gui Bing Hong ◽

Yi Hua Luo ◽

Kai Jen Chuang ◽

Hsiu Yueh Cheng ◽

Kai Chau Chang ◽

...

Keyword(s):

Silver Nanoparticles ◽

Electrical Resistivity ◽

Reaction Time ◽

Reaction Temperature ◽

Ph Value ◽

Chemical Reduction ◽

Flexible Substrate ◽

Synthesis Method ◽

Future Research ◽

Conductive Ink

In the scientific industry, sustainable nanotechnology has attracted great attention and has been successful in facilitating solutions to challenges presented in various fields. For the present work, silver nanoparticles (AgNPs) were prepared using a chemical reduction synthesis method. Then, a low-temperature sintering process was deployed to obtain an Ag-conductive ink preparation which could be applied to a flexible substrate. The size and shape of the AgNPs were characterized by ultraviolet–visible spectrophotometry (UV-Vis) and transmission electron microscopy (TEM). The experiments indicated that the size and agglomeration of the AgNPs could be well controlled by varying the reaction time, reaction temperature, and pH value. The rate of nanoparticle generation was the highest when the reaction temperature was 100 °C within the 40 min reaction time, achieving the most satisfactorily dispersed nanoparticles and nanoballs with an average size of 60.25 nm at a pH value of 8. Moreover, the electrical resistivity of the obtained Ag-conductive ink is controllable, under the optimal sintering temperature and time (85 °C for 5 min), leading to an optimal electrical resistivity of 9.9 × 10−6 Ω cm. The results obtained in this study, considering AgNPs and Ag-conductive ink, may also be extended to other metals in future research.

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