Determination of Antibacterial Efficacy of AgNPs Synthesized by Leaf extract of Azadirachta indica against Staphylococcus aureas and Bacillus cereus (original) (raw)
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SYNTHESIS OF BENIGN SILVER NANOPARTICLES TO ENHANCE ANTIBACTERIAL ACTIVITY OF AZADIRACHTA INDICA
International Journal of Agriculture, Environment and Bioresearch, 2019
Biologically synthesized nanomaterials and their industrial utilization have become an integral part of bionanotechnology. There is an increasing demand for silver nanoparticles (Ag-NPs) due to its wide properties in various fields of biomedical science including bio-sensing, drug delivery etc. Thus, the aim of the current study was to synthesize Ag-NPs by reducing the silver ions present in the silver nitrate (AgNO3) solution by green method to enhance antibacterial activity of a common medicinal plant Azadirachta indica. Initially, pure cultures of four gram positive (gm +ve) and eight gram negative (gm -ve) pathogenic bacteria were evaluated against the crude plant (leaf and bark) extracts and based on their susceptibility, two gm +ve and four gm -ve bacterial strains were finally selected. In case of crude extract, the highest zone of inhibition (13.00±1.00 mm) was observed against Staphylococcus aureus when treated with leaf samples, whereas it was 14.83±2.26 mm when treated with barks. Afterwards, Ag-NPs has been synthesized following greener method and the formation of Ag-NPs was confirmed by visual observation (colour change from pale yellow to dark brown) followed by Ultra-Violet Visible (UV-VIS) spectroscopy. Later, plant extracts with synthesized Ag-NPs were tested against same six bacterial strains and the obtained zone of inhibitions were compared with those of crude extract. As expected, both leaf and bark extracts showed increased zone of inhibition than previous. In this case, the diameter of the highest zone of inhibition was found 27.33±1.36 mm against S. aureus when treated with leaf extracts containing Ag-NPs and it was30.00±2.60 mm against the same bacterial strain. In case of bark extract with Ag-NPs. Finally, minimum inhibitory concentration (MIC) test was performed using both crude and Ag-NPs containing plant extracts. Significant differences were observed in MIC values between both types of plant extracts. The MIC value was found 0.312 mg/ml for both crude leaf and bark extracts and 0.078 mg/ml and 0.039 mg/ml for leaf and bark extract containing Ag-NPs, respectively. So, it could be concluded that the eco-friendly A. indica extracts (leaf and bark) can be used as an effective reducing agent for the synthesis of Ag-NPs and thus the antimicrobial activity of the selected medicinal plant can be enhanced by synthesized nanoparticles.
Science Research, 2020
Nanoparticles have emerged as a key player in modern medicine and involved in drug delivery, it can be manufactured using various approaches including chemical, physical, and biological methods. Nanoparticles are generally characterized by their size, morphology and surface charge using advanced microscopic techniques such as SEM and TEM. This study was aimed for synthesis and characterization of silver nanoparticle and to detect their antibacterial activity using Azadirachta indica (Neem) leaves extract. The results showed a visible change of colour after the addition of Neem leaf extract to AgNO 3 solution to dark brown which indicates the formation of silver nanoparticle. UV spectrophotometer showed absorbance peak in range of 390-700 nm, the result revealed the highest peak showed by concentration 1 ml at 428.80 nm. SEM and XRD analysis were used to characterize synthesize silver nanoparticles. The antibacterial activity against Gram positive Staphylococcus aureus and Gram negative Escherichia coli and Klebsiella spp Microorganisms was carried out using disc diffusion method, the results showed that the highest activity was 14 mm against S. aureus. A. indica silver nanoparticles can be used as a new nano drug in formulation and delivery. The synthesized silver nanoparticles are extremely important in various areas of life and are widely used for the benefit of human being.
Science Progress, 2021
A wide variety of methods have synthesized silver nanoparticles (Ag-NPs) in the recent past; however, biological methods have attracted much attention over the traditional chemical synthesis method due to being non-hazardous and eco-friendly. Here, a detailed and systemic study was performed to compare two different synthesis routes for Ag-NPs, that is, the chemical and the biological; their possible outcomes have also been described. Ag-NPs were synthesized chemically (cAg-NPs) using a chemical reductant and biologically (bAg-NPs) by using aqueous leaf extract of Azadirachta indica (neem). The synthesized nanoparticles were characterized using UVvisible spectrophotometry, FT-IR, EDX, and TEM. The average particle sizes (APS) of cAg-NPs were found to be 8 and 13 nm and of bAg-NPs to be 19 and 43 nm under different AgNO 3 concentrations. The antimicrobial tests of differently sized NPs were performed against Escherichia coli (Gram 2ve) and Staphylococcus aureus (Gram + ve). The results revealed that bAg-NPs of APS 43 nm were highly antimicrobial against both the tested bacterial stains followed by cAg-NPs of 8 nm. We found the effect of cAg-NPs to be size-dependent, whereas bAg-NPs showed a more significant antimicrobial effect than cAg-NPs.
Applied Nanoscience, 2017
In this study, green synthesis of silver nanoparticles was done using leaf extracts of Azadirachta indica. The flavonoids and terpenoids present in the extract act as both reducing and capping agent. Microbes (Escherichia coli and Gram-positive bacteria) were isolated from borewell water using selective media. The silver nanoparticles showed antimicrobial activities against Gram-positive bacteria and E. coli. However the silver nanoparticles were more effective against E. coli as compared to Gram-positive bacteria. Various techniques were used to characterize synthesized silver nanoparticles such as DLS and UV–visible spectrophotometer. The absorbance peak was in the range of 420–450 nm, that varied depending upon the variation in the concentration of neem extract. This is a very rapid and cost-effective method for generation of silver nanoparticle at room temperature, however, its exact dose in water purification has to be determined.
International Journal of Applied Sciences and Biotechnology
Silver nanoparticles (AgNPs) have been synthesized by green synthesis using Azadirachta indica leaf extract as both reducing and stabilizing agent. Synthesis of colloidal AgNPs was monitored by UV- visible spectroscopy. The UV- visible spectrum showed a peak at 455 nm corresponding to the plasmon absorbance of the silver nanoparticles. Crystallite structure of silver nanoparticles was studied using X-ray diffraction (XRD) analysis which revealed the face-centered cubic structure (FCC) with average particle size of 8.9 nm, calculated using Debye-Scherrer’s equation. Transmission electron microscopy (TEM) image revealed the agglomeration of small grain with particle size ranging from 2 to 14 nm. FCC crystalline nature was also evident from selected area electron diffraction (SAED) analysis. High purity of as-synthesized AgNPs was analyzed using energy dispersive X-ray (EDX) spectroscopy. Band gap energy was calculated to be 2.7 eV from UV- Visible spectra. 2,2-diphenyl-1-picrylhydrazy...
2015
Eco friendly and cost effective methods of green mediated synthesis of nanoparticles are the present research in the limb of nanotechnology. The present work leads to the synthesis of silver nanoparticles from 1 mM AgNO3 solution through various concentration of aqueous leaf extract of Azadirachta indica reducing as well as capping agent. The characteristics of silver nanoparticles were studied by using UVVIS spectroscopy, SEM and EDX. Ultraviolet scanning spectroscopy was used to detect the distinct absorption spectrum of silver nanoparticles. The peak value observed at 435 nm. The EDX spectrum of the silver nanoparticles confirmed the presence of elemental silver signal. The size of synthesized silver nanoparticle was 146 nm. Green synthesized silver nanoparticle showed zone of inhibition against isolated Gram positive (Micrococcus, Bacillus and Staphylococcus species) and Gram negative (Klebsiella species and E.coli) bacteria. Based on the result obtained it can be said that the ...
2021
Nanotechnology is the modern research field which deals with design, synthesis and manipulation of particles structure range from 1-100nm in dimension. A nanoparticle is ultra-fine unit with dimension less than 100 nm (1 nm=10-9 meter).Because of their small size they have unique characteristics and their applications in various field such as medicines, engineering and environmental remediation. Nanoparticles can be prepared by various aapproaches like physical, chemical and biological .The biological approach is the emerging approach because it is easier than other methods. In this green synthesis aqueous solution of extract of Azadirathcha indica and AgNo3 were taken for study. The nanoparticles were prepared by using plant extract and silver metal ions. The nanoparticles were characterized by different spectral methods like UV, IR, DLS, SEM, XRD and Zeta analysis.
Journal of Genetic Engineering and Biotechnology
Background The Ag-NPs by green synthesis has a notable interest because of their eco-friendliness, economic views, feasibility, and applications in a wide range. Herein, native plants of Jharkhand (Polygonum plebeium, Litsea glutinosa, and Vangueria spinosus) were selected for the current work of Ag-NP synthesis and further antibacterial activity. Green synthesis was performed for Ag-NPs using Silver nitrate solution as precursor and the dried leaf extract performs as a reductant and stabilizer here. Result Visually Ag-NP formation was observed along with a colour change and confirmed by UV-visible spectrophotometry on which an absorbance peak occurs at around 400–450nm. Further characterization was done on DLS, FTIR, FESEM, and XRD. Size around 45–86 nm of synthesized Ag-NPs was predicted through DLS. The synthesized Ag-NPs exhibited significant antibacterial activity against Bacillus subtilis (Gram-positive bacteria) and Salmonella typhi (Gram-negative bacteria). The finest antiba...
Chinese Journal of Physics, 2020
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Synthesis of silver nanoparticles using plants extract and analysis of their antimicrobial property
Journal of Saudi Chemical Society, 2012
Plants extract from Ocimum tenuiflorum, Solanum tricobatum, Syzygium cumini, Centella asiatica and Citrus sinensis was used for the synthesis of silver nanoparticles (Ag NPs) from silver nitrate solution. Ag NPs were characterized by UV-vis spectrophotometer, X-ray diffractometer (XRD), atomic force microscope (AFM) and scanning electron microscope (SEM). The formation and stability of the reduced silver nanoparticles in the colloidal solution were monitored by UV-vis spectrophotometer analysis. The mean particle diameter of silver nanoparticles was calculated from the XRD pattern according to the line width of the plane, refraction peak using the Scherrer's equation. AFM showed the formation of silver nanoparticle with an average size of 28 nm, 26.5 nm, 65 nm, 22.3 nm and 28.4 nm corresponding to O. tenuiflorum, S. cumini, C. sinensis, S. tricobatum and C. asiatica, respectively. SEM determination of the brown color stable samples showed the formation of silver nanoparticles and well dispersed nanoparticles could be seen in the samples treated with silver nitrate. Antimicrobial activity of the silver bio-nanoparticles was performed by well diffusion method against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumoniae. The highest antimicrobial activity of silver nanoparticles synthesized by S. tricobatum, O. tenuiflorum extracts was found against S. aureus (30 mm) and E. coli (30 mm) respectively. The Ag NPs synthesized in this process has the efficient antimicrobial activity against pathogenic bacteria. Of these, silver nanoparticles are playing a major role in the field of nanotechnology and nanomedicine.