scholarly journals Green Synthesis of Silver Nanoparticles Using Flower Extract of Hemigraphis colorata as Reducing Agent and its Biological Activity

2021 ◽  
Vol 10 (4) ◽  
pp. 2646-2654

Green synthesis of silver nanoparticles (Ag NPs) was performed using flower extract of Hemigraphis colorata (H. Colorata). Synthesized nanoparticles were characterized by UV-Visible Spectrophotometer (UV-Vis), Fourier Transform Infrared (FT-IR), Scanning Electron Microscope (SEM), and Transmission Electron Microscope (TEM-SAED). , The crystalline nature of the sample was examined by an X-ray diffraction study (XRD). The UV-Visible spectrum showed surface plasma resonance (SPR) at 360 nm revealed the formation of nanoparticles, SEM and TEM exhibited spherical shape particles with an average size between 10-20 nm. The valuation of the antibacterial and antifungal study revealed its efficiency in killing bacteria and fungi.

Author(s):  
Is Fatimah ◽  
Habibi Hidayat ◽  
Bambang Nugroho ◽  
Saddam Husein

Background: Green synthesis method of nanoparticles has been developed for several years. Besides providing an environmental-friendly process, the green synthesis of nanoparticles using plant extract provides a synergistic effect of the secondary metabolite. In recent times, the study involving the intensification process in nanoparticle formation also attracts great attention. This research deals with the green synthesis of silver nanoparticles using Datura metel flower extract as an antibacterial agent. The use of an ultrasound-assisted method for the synthesis is also investigated in this study. Methods: Synthesis of silver nanoparticles (AgNPs) using Datura metel flower extract under ultrasound-assisted method has been conducted. Evaluation of the successful synthesis was done using UV-visible spectrophotometry, particle size analyzer, x-ray diffraction, and transmission electron microscopy. The prepared AgNPs were tested as antibacterial against S. aureus, K. pneumoniae, S. pyogenes, and E. coli. Results: The ultrasound-assisted synthesis of AgNPs produces particles ranging from 25-70 nm in size; meanwhile, the reflux method demonstrated the size of 50-170 nm. These particle sizes represent the effect of the antibacterial activity as the ultrasound-assisted synthesized Ag NPs have a higher inhibition zone towards all tested bacteria. Subsequently, these data presented the applicability of Ag NPs synthesis using an ultrasound method as a potential candidate for biomedical applications. Conclusion: The profile of UV-Visible spectra and particle size analyses demonstrated the applicability of the ultrasound technique to produce a smaller size of the nanoparticles with higher antibacterial activity.


2021 ◽  
Author(s):  
Manal F. abou Taleb ◽  
Faten Ismail Abou El Fadl ◽  
Hanan Albalwi ◽  
Mohamed M. Ibrahim

Abstract Silver nanoparticles (Ag NPs) are widely used as engineered nanomaterials in many advanced nanotechnologies, due to their versatile, easy and cheap preparations combined with peculiar chemical-physical properties. Their increased production and integration in environmental applications including water treatment raise concerns for their impact on humans and the environment. In this study, gamma radiation dose of 20 kGy was utilized to induce the synthesis silver nanoparticles (Ag NPs) in the alginate micro beads to prepare calcium Alginate/Ag (Ca-ALG/Ag) nanocomposite beads. These beads were then used to degrade toxic basic dyes in waste water. Initially, Ca-ALG /Ag nanocomposite beads were synthesized and characterized using Ultra Violet-visible spectrum (UV-Vis), Scanning Electron Microscope (SEM), X-Ray Diffraction (XRD) and Transmission Electron Microscope (TEM) for confirming the formation of Ag NPs and morphological study. The catalytic efficiency of the resulting Ca-ALG/Ag nanocomposite beads is evaluated for the degradation of dyes such sandocryl blue dye in the presence of NaBH4. The catalytic degradation of sandocryl blue dye was very fast in the present conditions: 0.1 g of catalyst 5 ml NaBH4 and the optimum time for complete reduction was 30 min. The pseudo-first order, pseudo second order and intra particle diffusion model used to evaluate the kinetic models and the mechanism of the degradation. Results showed that the degradation kinetics best fit the pseudo-second-order model and Langmuir isotherm model. The Biopolymer-based nanocomposite beads of calcium alginate, and Ag NPs can be applied to reduce dyestuff, where it is economically viable and environmentally friendly.


2007 ◽  
Vol 124-126 ◽  
pp. 1189-1192 ◽  
Author(s):  
Kwi Jong Lee ◽  
Young Il Lee ◽  
In Keun Shim ◽  
Byung Ho Jun ◽  
Hye Jin Cho ◽  
...  

The synthesis and characterization of polymer-stabilized silver nanoparticles (Ag NPs) for water-based silver inks are studied. In order to synthesize Ag NPs with spherical shape, the conventional polyol processes require an excess of poly(vinyl pyrrolidone) (PVP) (10 ~ 1000 times than AgNO3) and therefore result in low productivity per reactor volume. In this study, poly(acrylic acid) (PAA) with carboxylic acid group was used instead of PVP. Even at less molar ratio of PAA to AgNO3 (< 2), the spherical Ag NPs with average size of 30 nm were successfully synthesized at 100 gram-scale with high reaction yield of 90%. Furthermore, the Ag NPs were dispersed into alcohol-based solvent and then patterned into metallic lines through inkjet printing technology.


2021 ◽  
Author(s):  
Ola M. Gomaa ◽  
Amar Alrshim ◽  
Anindya Chanda

Abstract The present work aims to study the removal of Polyvinylpyrrolidone coated silver nanoparticles (PVP-Ag-NPs) using Aspergillus niger and depict the role of exopolysaccharides in the removal process. Our results show that the majority of PVP-Ag-NPs were attached to fungal pellets. About 74% and 88% PVP-Ag-NPs were removed when incubated with A. niger pellets and exopolysaccharide-induced A. niger pellets, respectively. Ionized Ag decreased by 553 and 1290 fold under the same conditions as compared to stock PVP-Ag-NP. PVP-Ag-PVP resulted in an increase in reactive oxygen species (ROS) in 24h. The UV-Visible spectrum shows the disappearance of Ag characteristic peak and the broadness of the spectrum suggested an increase in size. Dynamic Light Scattering results showed an increase in PVP-Ag-NPs size from 28.4 nm to 115.9 nm for A. niger pellets and 160.3 nm after removal by stress-induced A. niger pellets and further increased to 650.1 nm for in vitro EPS removal. Our findings show that EPS can be used for nanoparticle removal, by increasing the net size of nanoparticles in aqueous media, this will, in turn, facilitate its filtration through conventional filtration techniques commonly used at wastewater treatment plants.


Author(s):  
S. Prathimaa ◽  
J. Anbumalarmathi ◽  
S. Aruna Sharmili

Plant mediated fabrication of nanoparticles and nanomaterials are gaining momentum as it is eco-friendly and cost-effective. In the present study, we synthesis of Silver nanoparticles using aqueous extract of  Quercus infectoria nuts and Daucus carota subsp sativum leaves. The surface plasma resonance at 417 and 450 nm for Q. infectoria and D. carota respectively confirmed the formation of AgNPs. Scanning Electron Microscopic (SEM) confirmed the spherical shape of the nanoparticles, which had an average size of 67.5 nm and 49.2 nm for Q. infectoria nanoparticles (QAgNPs)and D. carota nanoparticles (DAgNPs). The elemental composition by Energy-Dispersive X-ray analysis of the nanoparticle showed an atomic percentage of silver as 73.64 % and 75.93% for Q. infectoria and D. carota.FT- IR analysis of the plant extracts and synthesized silver nanoparticles showed the presence of various functional groups. The total antioxidant activity of QAgNPs was 81.18% and that of DAgNPs was 73.36%. The QAgNPs and DAgNPs exhibited antibacterial activity against B. subtilis, E. coli and S. aureus. The percentage of cell viability for QAgNPs and DAgNPs assessed using HeLa cells was 21.1% and 6% respectively.


2020 ◽  
Vol 17 (7) ◽  
pp. 2882-2889
Author(s):  
Mustafa Mudhafar ◽  
Ismail Zainol ◽  
C. N. Aiza Jaafar ◽  
H. A. Alsailawi ◽  
Alhussein Arkan Majhool

The effect of the synthesis technique on the shape and size of Ag-NPs has been reported. Ag nanoparticles has been produced by using two techniques, green synthesis and microwave-assisted green synthesis methods (MSGS), respectively. The current research was included to use a stabilizer and reducing agents from natural sources to get the non-toxic and environmentally friendly product, via using Melia dubia (neem) (M. dubia) and fish scales collagen (FsCol). The nanoparticles of Ag was portrayed by using Scanning electron microscope (SEM), Ultraviolet-visible spectroscopy (UV-vis), Energy-dispersive X-ray spectroscopy (EDX), Fourier-transform infrared spectroscopy (FTIR), Dynamic Light Scattering (DLS) and X-ray Powder Diffraction (XRD). Two different absorbance peaks were noticed in UV-vis and located at 454 nm silver nanoparticles-1 (AgNPs-1) and 446 nm silver nanoparticles-2 (AgNPs-2). SEM was shown two different shapes rod (AgNPs-1) and spherical (AgNPs-2 shapes. EDX confirmed the presence of Ag as a single element at 3 KeV. FTIR was shown fictional groups that were surrounded by silver nanoparticles C2H2 C=O, N-H groups was an indication. XRD was shown thus that the AgNPs formed in this modern prepared are crystalline with two different sizes 120.20 and 84.30 nm, corresponding to AgNPs-1 and AgNPs-2. The Z-average in DLS for AgNPs-1 has been shown average size at 437.8 nm while AgNPs-2 was shown 121 nm in its size.


2015 ◽  
Vol 1131 ◽  
pp. 223-226 ◽  
Author(s):  
Pranlekha Traiwatcharanon ◽  
Kriengkri Timsorn ◽  
Chatchawal Wongchoosuk

In this work, we have presented the green synthesis of silver nanoparticles (Ag-NPs) using extracts of Pistiastratiotes L. as reducing agent. The silver nitrate (AgNO3) solutions were used as precursor. The experiments were performed under irradiation with a light that can help to increase the activation for reduction of silver ions (Ag+) to metallic silver (Ag0). The effects of pH on the nature of Ag-NPs have been systematically studied by using ultraviolet-visible spectroscopy (UV-Vis) and transmission electron microscopy (TEM). The results show that the synthesis of Ag-NPs in acidic medium gives smaller size than that in basic medium. A number of synthesized Ag-NPs increase with increasing the concentrations of acidic/basic medium. All synthesized Ag-NPs have spherical shape.


2018 ◽  
Vol 1 (2) ◽  
pp. 68
Author(s):  
Verry Andre Fabiani ◽  
Febry Sutanti ◽  
Desti Silvia ◽  
Megawati Ayu Putri

An environment friendly technique for green synthesis of silver nanoparticles has been reported. Silver nanoparticle have been synthesized using water extract of leaves of pucuk idat (Cratoxylum glaucum), commonly known as local Bangka plant. The flavonoid and tannin present in the extract act as reducing agent. AgNO3 0,05 M solution was reducing using the extract at room temperature by stirring. Color changing of the solution was detected at 30 minutes reaction time. The color tends to be darker by the increasing of reaction time. Various techniques used to characterize synthesized nanoparticles are UV-Visible spectrophotometer, x-ray diffraction (XRD) and scanning electron microscopy (SEM). UV-Visible spectrophotometer showed absorbance peak in 405 nm, the XRD shows that silver nanoparticles formed are crystalline. The average particle size of Ag nanoparticles estimated from the Scherrer formula is 35,59 nm, while SEM image shows shape of silver nanoparticle is random and some spherical shape.


2021 ◽  
Author(s):  
Ola M. Gomaa ◽  
Amar Elrshim ◽  
Anindya Chanda

Abstract The rapidly growing production and applications of Engineered Nanoparticles (ENPs) foresees a concomitant increase in the exposure of humans to their potential toxic effects through accidental release to the environment. Due to the limited and/or contaminated water resources, the need to re-use treated water has become imperative. The present work aims to study the removal of Polyvinylpyrrolidone coated silver nanoparticles (PVP-Ag-NPs) using Aspergillus niger and depict the role of exopolysaccharides in the removal process. Our results show that the majority of PVP-Ag-NPs were attached to fungal pellets. About 74% and 88% PVP-Ag-NPs were removed when incubated with A. niger pellets and exopolysaccharide-induced A. niger pellets, respectively. Ionized Ag decreased by 553 and 1290 fold under the same conditions as compared to stock PVP-Ag-NP. The increase in PVP-Ag-PVP concentrations resulted in an increase in reactive oxygen species (ROS) in 24h. The UV-Visible spectrum shows the disappearance of Ag characteristic peak and the broadness of the spectrum suggested an increase in size. Dynamic Light Scattering results showed an increase in PVP-Ag-NPs size from 28.4 nm to 115.9 nm for A. niger pellets and 160.3 nm after removal by stress-induced A. niger pellets and further increased to 650.1 nm for in vitro EPS removal. Our findings show that EPS can be used for nanoparticle removal, by increasing the net size of nanoparticles in aqueous media, this will, in turn, facilitate its filtration through conventional filtration techniques commonly used at wastewater treatment plants.


Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 277
Author(s):  
Mai I. El-kaliuoby ◽  
Alaa M. Khalil ◽  
Ahmed M. El-Khatib ◽  
Nader Shehata

The over-reliance on antibiotics and their enormous misuse has led to warnings of a future without effective medicines and so, the need for alternatives to antibiotics has become a must. Non-traditional antibacterial treatment was performed by using an aray of nanocomposites synergised with exposure to electromagnetic waves. In this manuscript, electrospun poly(vinyl alcohol) (PVA) nanofiber mats embedded with silver nanoparticles (Ag NPs) were synthesized. The nanocomposites were characterized by Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM), Current-Voltage (I-V) curves, and Thermogravimetric analysis (TGA) along with analysis of antibacterial impact against E. coli and S. aureus bacteria, studied by bacterial growing analysis, growth kinetics, and cellular cytotoxicity. The results indicated a spherical grain shape of silver of average size 20 nm and nanofibers’ mean diameter of less than 100 nm. The nanocomposite mats showed good exposure to bacteria and the ability to sustain release of silver for a relatively long time. Moreover, the applied electromagnetic waves (EMWs) were shown to be a synergistic co-factor in killing bacteria even at low concentrations of Ag NPs. This caused pronounced alterations of the bacterial preserved packing of the cell membrane. Thereby, the treatment with nanocomposite mats under EM wave exposure elucidated maximum inhibition for both bacterial strains. It was concluded that the functioning of nanofiber with silver nanoparticles and exposure to electromagnetic waves improved the antibacterial impact compared to each one alone.


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