scholarly journals A Green Approach to Synthesize Silver Nanoparticles in Starch-co-Poly(acrylamide) Hydrogels by Tridax procumbens Leaf Extract and Their Antibacterial Activity

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Siraj Shaik ◽  
Madhusudana Rao Kummara ◽  
Sudhakar Poluru ◽  
Chandrababu Allu ◽  
Jaffer Mohiddin Gooty ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Leaf Extract ◽  
Silver Ions ◽  
Inhibition Zone ◽  
Zone Method ◽  
Green Approach ◽  
Tridax Procumbens ◽  
Poly Acrylamide

A series of starch-co-poly(acrylamide) (starch-co-PAAm) hydrogels were synthesized by employing free radical redox polymerization. A novel green approach, Tridax procumbens (TD) leaf extract, was used for reduction of silver ions (Ag+) into silver nanoparticles in the starch-co-PAAm hydrogel network. The formation of silver nanoparticles was confirmed by UV-visible spectroscopy (UV-Vis), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (X-RD) studies. 22% of weight loss difference between hydrogel and silver nanocomposite hydrogel (SNCH) clearly indicates the formation of silver nanoparticles by TGA. TEM images indicate the successful incorporation of silver nanoparticles ranging from 5 to 10 nm in size and spherical in shape with a narrow size distribution. These developed SNCHs were used to study the antibacterial activity by inhibition zone method against gram-positive and gram-negative bacteria such as Bacillus and Escherichia coli. The results indicated that these SNCHs can be used potentially for biomedical applications.

scholarly journals Carbene modification and reversible crosslinking of silver nanoparticles for controlled antibacterial activity

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Liling Jing ◽  
Mark G. Moloney ◽  
Hao Xu ◽  
Lian Liu ◽  
Wenqiang Sun ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Photoelectron Spectroscopy ◽  
Inhibition Zone ◽  
Insertion Reaction ◽  
Ag Nps ◽  
Zone Method ◽  
Transmission Electron

Abstract Silver nanoparticles (Ag NPs) system capable of exhibiting different particle size at different temperature was developed, which depended on the extent of Diels–Alder (DA) reaction of bismaleimide with furan. Thus, Ag NPs were functionalized on the surface by a furyl-substituted carbene through an insertion reaction. Subsequent reversible DA crosslinking achieved a controlled aggregation with different particle size, which gives a series of different antibacterial activity. These Ag NPs were characterized by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), and Nanoparticle Size Analyzer. The aggregation of the Ag NPs could be reliably adjusted by varying the temperature of DA/reverse-DA reaction. The antibacterial activity was assessed using the inhibition zone method against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), which decreased first and then increased in agreement with the size evolution of Ag NPs. This approach opens a new horizon for the carbene chemistry to modify silver nanoparticles with variable size and give controlled antibacterial activity.

scholarly journals PSIDIUM GUAJAVA: A NOVEL PLANT IN THE SYNTHESIS OF SILVER NANOPARTICLES FOR BIOMEDICAL APPLICATIONS.

2018 ◽  
Vol 11 (1) ◽  
pp. 341
Author(s):  
Sharmila C ◽  
Ranjith Kumar R ◽  
Chandar Shekar B
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Biomedical Applications ◽  
Leaf Extract ◽  
Cost Effective ◽  
Psidium Guajava ◽  
Tem Analysis ◽  
X Ray ◽  
Green Route

 Objective: Synthesis of silver nanoparticles (AgNPs) using a simple, cost-effective and environmentally friendly green route approach and to study the antibacterial activity of AgNPs against human pathogens.Methods: Green route approach is used to synthesize AgNPs using Psidium guajava leaf extract. Fourier transform infrared (FTIR) was used to identify the presence of the functional group. X-ray diffraction (XRD) was used to analyze the structure of prepared AgNPs. Energy dispersive X-ray was used to the characteristic to the composition of the prepared nanoparticles. Size and morphology of the prepared AgNPs were investigated using field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) analysis. Antibacterials efficiency of prepared AgNPs was tested against Escherichia coli and Staphylococcus aureus by well diffusion methods.Results: FTIR study shows the presence of different functional groups present in the leaves mediated AgNPs. The XRD studies yield diffraction peaks corresponding to face-centered cubic structure of Ag crystals. Spherical shaped AgNPs with a particle size of about ~55 nm were evidenced using FESEM and TEM analysis. Energy dispersive spectrum of the synthesized AgNPs confirms the presence of silver in the prepared nanoparticles. From UV-VIS analysis it is shown that the absorption band was red-shifted from 430 nm to 456 nm. The prepared AgNPs shows good antibacterial activity against E. coli and S. aureus.Conclusions: P. guajava leaf extract is a potential reducing agent to synthesize AgNPs. The green synthesis approach provides cost-effective and eco-friendly nanoparticles, which could be used in biomedical applications.

Green Synthesis of Silver Nanoparticles Using Hibiscus rosa-sinensis Leaf Extract

2019 ◽  
Vol 9 (4) ◽  
pp. 472-478
Author(s):  
Hooi Chien Ng ◽  
Cheng Seong Khe ◽  
Xin Hui Yau ◽  
Wei Wen Liu ◽  
Azizan Aziz
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Leaf Extract ◽  
Synthesis Method ◽  
Cost Effective ◽  
Biological Properties ◽  
Capping Agent ◽  
Green Approach ◽  
Selected Area Electron Diffraction ◽  
High Resolution Tem

Background: Owing to their remarkable chemical, physical and biological properties, silver nanoparticles have been widely used in water purification, electronics, bio-sensing, clothing, food industry, paint and medical devices. Various approaches, such as using harsh reducing and stabilising agents for reverse micelle and thermal decomposition, were proposed for silver nanoparticle production. However, these methods are not eco-friendly. Thus, the aim of this paper is to synthesise silver nanoparticles through a cost-effective and environmentally friendly approach. Materials and Methods: A green approach was presented for the synthesis of silver nanoparticles. This approach involved the treatment of silver nitrate and hibiscus leaf extract, which acts as reducing and capping agent. The synthesis was performed at room temperature. The resulting silver nanoparticles were characterised by scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution TEM (HRTEM) and Fourier transform infrared (FTIR) spectroscopy. Results: Spherical, rod-like, hexagonal and triangular silver nanoparticles were obtained through the proposed synthesis method. The crystalline nature of each nanoparticle was revealed by XRD and selected area electron diffraction (SAED). The average spherical size of the silver nanoparticles produced in this route was 44.3 nm. The obtained FTIR band at 1622 cm-1 corresponded to the C=O stretch in the amine I group, which is commonly found in protein. Thus, the protein was believed to serve as capping agent that was responsible for the stabilisation of silver nanoparticles. Conclusion: In conclusion, silver nanoparticles had been successfully synthesised using hibiscus leaf extract and a plausible formation mechanism of silver nanoparticles was proposed.

scholarly journals PSIDIUM GUAJAVA: A NOVEL PLANT IN THE SYNTHESIS OF SILVER NANOPARTICLES FOR BIOMEDICAL APPLICATIONS.

2018 ◽  
Vol 11 (1) ◽  
pp. 341 ◽  
Author(s):  
Sharmila C ◽  
Ranjith Kumar R ◽  
Chandar Shekar B
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Biomedical Applications ◽  
Leaf Extract ◽  
Cost Effective ◽  
Psidium Guajava ◽  
Tem Analysis ◽  
X Ray ◽  
Green Route

 Objective: Synthesis of silver nanoparticles (AgNPs) using a simple, cost-effective and environmentally friendly green route approach and to study the antibacterial activity of AgNPs against human pathogens.Methods: Green route approach is used to synthesize AgNPs using Psidium guajava leaf extract. Fourier transform infrared (FTIR) was used to identify the presence of the functional group. X-ray diffraction (XRD) was used to analyze the structure of prepared AgNPs. Energy dispersive X-ray was used to the characteristic to the composition of the prepared nanoparticles. Size and morphology of the prepared AgNPs were investigated using field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) analysis. Antibacterials efficiency of prepared AgNPs was tested against Escherichia coli and Staphylococcus aureus by well diffusion methods.Results: FTIR study shows the presence of different functional groups present in the leaves mediated AgNPs. The XRD studies yield diffraction peaks corresponding to face-centered cubic structure of Ag crystals. Spherical shaped AgNPs with a particle size of about ~55 nm were evidenced using FESEM and TEM analysis. Energy dispersive spectrum of the synthesized AgNPs confirms the presence of silver in the prepared nanoparticles. From UV-VIS analysis it is shown that the absorption band was red-shifted from 430 nm to 456 nm. The prepared AgNPs shows good antibacterial activity against E. coli and S. aureus.Conclusions: P. guajava leaf extract is a potential reducing agent to synthesize AgNPs. The green synthesis approach provides cost-effective and eco-friendly nanoparticles, which could be used in biomedical applications.

Green Synthesis of Silver Nanoparticles by Allamanda cathartica L. Leaf Extract and Evaluation for Antimicrobial Activity

2013 ◽  
Vol 6 (4) ◽  
pp. 2260-2268
Author(s):  
M. Linga Rao ◽  
Bhumi G ◽  
Savithramma N
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Leaf Extract ◽  
Fusarium Species ◽  
Inhibition Zone ◽  
Fungal Species ◽  
Green Technology ◽  
Metallic Silver ◽  
Synthesis Of Nanoparticles ◽  
Aqueous Leaf Extract

Silver nanoparticles (SNPs) exhibit tremendous applications in medicine as antimicrobial agent.  The use of different parts of plants for the synthesis of nanoparticles is considered as a green technology as it does not involve any harmful chemicals.  In the present study, we report a rapid biosynthesis of silver nanoparticles from aqueous leaf extract of medicinal plant Allamanda cathartica.  The active phytochemicals present in the plant were responsible for the quick reduction of silver ion to metallic silver nanoparticles. The reduced silver nanoparticles were characterized by using UV-Vis spectrophotometry, Scanning Electron Microscope (SEM), Energy Dispersive Analysis of X-ray (EDAX) and Atomic Force Microscopy (AFM).  The spherical shaped silver nanoparticles were observed and it was found to 19-40 nm range of size.  These phytosynthesized SNPs were tested for their antimicrobial activity and it analyzed by measuring the inhibitory zone. A. cathartica aqueous leaf extract of SNPs showed highest toxicity to Pseudomonas followed by Klebsiella, Bacillus and E. coli and lowest toxicity towards Proteus. In fungal species, highest inhibition zone was noted against Rhizopus followed by Curvularia, Aspergillus flavus and Aspergillus niger and minimum inhibition zone was observed against Fusarium species.  These results suggest a promising potential of Indian plant-based green chemistry for production of SNPs for biomedical and nanotechnology applications.

scholarly journals Biosynthesis, characterization, and antibacterial activity of ZnO nanoaggregates using aqueous extract from Anacardium occidentale leaf: comparative study of different precursors

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Eric Kwabena Droepenu ◽  
Ebenezer Aquisman Asare ◽  
Boon Siong Wee ◽  
Rafeah Binti Wahi ◽  
Frederick Ayertey ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Antibacterial Activity ◽  
Comparative Study ◽  
Aqueous Extract ◽  
Zinc Chloride ◽  
Zinc Acetate ◽  
Zinc Acetate Dihydrate ◽  
Inhibition Zone ◽  
Anacardium Occidentale ◽  
Acetate Dihydrate

Abstract Background Various parts of Anacardium occidentale plant possess curative qualities like antidiabetic, anti-inflammatory, antibacterial, antifungal, and antioxidant. Aqueous extract of this plant leaf was used in biosynthesizing zinc oxide (ZnO) nanoaggregates using two precursors of zinc salt (zinc acetate dihydrate [Zn(CH3COO)2∙2H2O] and zinc chloride [ZnCl2]). The synthesized ZnO samples were used in a comparative study to investigate the antibacterial activity against selected Gram-positive and Gram-negative microbes [Staphylococcus aureus, Exiguobacterium aquaticum (Gram +ve) and Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii (Gram −ve)]. The synthesized ZnO nanoaggregates from the two precursors were characterized using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive x-ray spectroscopy (EDX) techniques. Results Micrographs of SEM and TEM confirmed nanoparticles agglomerated into aggregates. While spherical nanoaggregates were identified in samples prepared from Zn(CH3COO)2∙2H2O, flake-like structures were identified in samples synthesized from ZnCl2. Particle size determined by TEM was 107.03 ± 1.54 nm and 206.58 ± 1.86 nm for zinc acetate dihydrate and zinc chloride precursors respectively. ZnO nanoaggregate synthesized using zinc acetate as precursor gave higher antibacterial activity than its counterpart, zinc chloride with K. pneumonia recording the highest inhibition zone of 2.08 ± 0.03 mm (67.53%) whereas S. aureus recorded the least inhibition zone of 1.06 ± 0.14 mm (34.75%) for ZnO nanoaggregate from zinc chloride precursor. Also, antibacterial activity increases with increasing concentration of the extract in general. However, A. baumannii, E. aquaticum, and K. pneumoniae did not follow the continuity trend with regards to the 250 ppm and 500 ppm concentrations. Conclusion Biosynthesis of ZnO nanoaggregates using aqueous extract of A. occidentale leaf from zinc acetate dihydrate and zinc chloride as precursors was successful with the formation of nanospheres and nanoflakes. The study suggested that A. occidentale sp. could be an alternative source for the production of ZnO nanoparticles and are efficient antibacterial compounds against both Gram +ve and Gram −ve microbes with its promising effect against infectious bacteria.

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