scholarly journals Green synthesis of Microalgal biomass-silver nanoparticles composite showing antimicrobial activity and heterogenous catalysis of nitrophenol reduction

2021 ◽  
Author(s):  
Sushree S. Priyadarshini ◽  
Shradhanjali Sethi ◽  
Shweta Rout ◽  
Pravat Manjari Mishra ◽  
Nilotpala Pradhan
Keyword(s):  
Silver Nanoparticles ◽  
Pathogenic Bacteria ◽  
Integrated Approach ◽  
Diffusion Method ◽  
Potential Candidate ◽  
Microalgal Biomass ◽  
Heterogenous Catalysis ◽  
Open Raceway Pond ◽  
Nitrophenol Reduction ◽  
Heterogenous Catalyst

Abstract In this study we have demonstrated an integrated approach for utilization of microalga Scenedesmus sp, generated during CO2 sequestration, in fabrication of catalytic and antimicrobial silver nanoparticles composite. The algal biomass was grown in open raceway pond of 30,000 L scale for CO2 sequestration, after which it was harvested and dried. The dried biomass served as a reducing and immobilizing agent for silver nanoparticles. The biomass-silver nanoparticles composite was used for the first time, as a heterogenous catalyst for reduction of a prominent industrial pollutant, p-Nitrophenol, in aqueous medium under ambient condition. Series of experiments were conducted to evaluate the effect of calcination temperature, load and reuse of the material on its catalytic efficiency. The calcined composite material was found to be an excellent catalyst for reduction of p-Nitrophenol. As low as 5 mg mL− 1 calcined material could catalyse the reduction of more than 95% p-Nitrophenol at the rate of 0.60 mg L− 1 min − 1 in aqueous solution at 10 ppm concentration. The efficiency of catalysis was evaluated for ten cycles of reuse. The material was found to be a potential candidate as a reusable heterogenous catalyst for designing continuous flow system for remediation of industrial effluents rich in p-Nitrophenol. Furthermore the material served as a good antimicrobial agent against pathogenic bacteria and fungi. Two strains each of gram + ve and gram –ve bacteria and three strains of fungi were used in the antimicrobial studies using well diffusion method.

scholarly journals Optical characterization and concentration-dependent antibacterial activity of silver nanoparticles (AgNPs) using aqueous Melastoma malabathricum extract against Staphylococcus aureus

2020 ◽  
Vol 11 (4) ◽  
pp. 5382-5387
Author(s):  
Irshad Ul Haq Bhat ◽  
Maisarah Binti Alias
Keyword(s):  
Staphylococcus Aureus ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Functional Groups ◽  
Diffusion Method ◽  
Synthetic Approach ◽  
Potential Candidate ◽  
X Ray ◽  
Melastoma Malabathricum ◽  
Resonance Band

The approach towards green synthetic methods has been enormously encouraged to synthesise nanoparticles for various uses. In this study, the one-pot synthetic method was adapted to synthesise silver nanoparticles (AgNPs) using Melastoma malabathricum (M. malabathricum) aqueous extract. The formation of AgNPs was confirmed by observing the results obtained by optical characterisation methods. The plasma resonance band along with shoulder at 375 nm and 595 nm, respectively, in Uv-Visible spectra supported the conversion of silver (Ag) to AgNPs reduced by functional groups present in the plant extract. The size of AgNPs was 31 nm and cubic in shape as confirmed by X-ray diffractometry (XRD) using Scherer equation. X-Ray Fluorescence (XRF) results also confirmed the presence of silver. The FTIR characterisation confirmed the presence of reducing functional groups. The antibacterial activity of AgNPs against Staphylococcus aureus (S. aureus) was carried out by disc diffusion method with increasing concentration of AgNPs, and enhanced inhibition zone was observed. The AgNPs obtained can be further explored against different bacterial strains and can a potential candidate as an antibacterial agent using the green synthetic approach.

Biological Applications, Green Synthesis, Characterization of Silver Nanoparticles (AgNPs) Using Artemisia annua L.

2021 ◽  
Vol 13 (7) ◽  
pp. 1304-1309
Author(s):  
Hamed A. Ghramh ◽  
Rahmah N. Al-Qthanin ◽  
Zubair Ahmad ◽  
Essam H. Ibrahim ◽  
Mona Kilany ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Artemisia Annua ◽  
Diffusion Method ◽  
Biological Applications ◽  
Disk Diffusion Method ◽  
Vis Spectroscopy ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis

ABSTRACTThis article reports on the silver nanoparticles (AaAgNPs) that were green-synthesized by using Artemisia annua L. extract (AaExt) and their collective biological applications. Active biomolecules in the extract and extract containing AgNPs were characterized using Fourier-transform-infrared-spectroscopy (FTIR) and AgNPs were monitored by UV/vis spectroscopy and SEM (scanning electron microscopy) analysis. The size of the particle is around 100 nm. The antibacterial activity was measured by the disk diffusion method against the Gram-negative/positive pathogenic bacteria. The extract and extract containing AgNPs showed a significant antibacterial activity. Cytotoxic potential of the synthesized AgNPs was analyzed against the rat splenocytes. The results showed that there were cytotoxic effects of A. annua leaves extract but stimulatory effects when the extract contained AgNPs on normal splenocytes. Extract of A. annua showed very little increase in liver enzymes. Regarding the larvicidal activity, the extract containing AgNPs was more effective than the crude leaves extract against 4th instar larvae of Culex pipiens (LC50 = 171.378 ppm) compared to the plant extract (LC50 = 5389.726 ppm) by about 31.449 folds.

scholarly journals Green synthesis of silver nanoparticles in aloe vera plant extract prepared by a hydrothermal method and their synergistic antibacterial activity

2016 ◽  
Author(s):  
Patcharaporn Tippayawat ◽  
Nutthakritta Phromviyo ◽  
Parichart Boueroy ◽  
Apiwat Chompoosor
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Green Synthesis ◽  
Hydrothermal Method ◽  
Plant Extract ◽  
Pathogenic Bacteria ◽  
Antibacterial Effect ◽  
Aloe Vera ◽  
Diffusion Method

Background: There is worldwide interest in silver nanoparticles (AgNPs) synthesized by various chemical reactions for use in applications exploiting their antibacterial activity, even though these processes exhibit a broad range of toxicity in vertebrates and invertebrates alike. To avoid the chemical toxicity, biosynthesis (green synthesis) of metal nanoparticles is proposed as a cost-effective and environmental friendly alternative. Aloe vera leaf extract is a medicinal agent with multiple properties including an antibacterial effect. Moreover the constituents of aloe vera leaves include lignin, hemicellulose, and pectins which can be used in the reduction of silver ions to produce as AgNPs@aloe vera (AgNPs@AV) with antibacterial activity. Methods: AgNPs were prepared by an eco-friendly hydrothermal method using an aloe vera plant extract solution as both a reducing and stabilizing agent. AgNPs@AV were characterized using XRD and SEM. Additionally, an agar well diffusion method was used to screen for antimicrobial activity. MIC and MBC were used to correlate the concentration of AgNPs@AV its bactericidal effect. SEM was used to investigate bacterial inactivation. Then the toxicity with human cells was investigated using an MTT assay. Results: The synthesized AgNPs were crystalline with sizes of 70.70 ± 22-192.02 ± 53 nm as revealed using XRD and SEM. The sizes of AgNPs can be varied through alteration of times and temperatures used in their synthesis. These AgNPs were investigated for potential use as an antibacterial agent to inhibit pathogenic bacteria. Their antibacterial activity was tested on S. epidermidis and P. aeruginosa. The results showed that AgNPs had a high antibacterial which depended on their synthesis conditions, particularly when processed at 100 oC for 6 h and 200 oC for 12 h. The cytotoxicity of AgNPs was determined using human PBMCs revealing no obvious cytotoxicity. These results indicated that AgNPs@AV can be effectively utilized in pharmaceutical, biotechnological and biomedical applications. Discussion: Aloe vera extract was processed using a green and facile method. This was a hydrothermal method to reduce silver nitrate to AgNPs@AV. Varying the hydrothermal temperature provided the fine spherical shaped nanoparticles. The size of the nanomaterial was affected by its thermal preparation. The particle size of AgNPs could be tuned by varying both time and temperature. A process using a pure AG phase could go to completion in 6h at 200 oC, whereas reactions at lower temperatures required longer times. Moreover, the antibacterial effect of this hybrid nanomaterial was sufficient that it could be used to inhibit pathogenic bacteria since silver release was dependent upon its particle size. The high activity of the largest AgNPs might have resulted from a high concentration of aloe vera compounds incorporated into the AgNPs during hydrothermal synthesis.

scholarly journals Biogenic Synthesis of Silver Nanoparticles Using Scenedesmus abundans and Evaluation of Their Antibacterial Activity

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Nafe Aziz ◽  
Tasneem Fatma ◽  
Ajit Varma ◽  
Ram Prasad
Keyword(s):  
Silver Nanoparticles ◽  
Pathogenic Bacteria ◽  
Visible Spectrum ◽  
Potential Candidate ◽  
Gradual Change ◽  
Antibacterial Efficacy ◽  
Silver Particles ◽  
Biogenic Synthesis ◽  
E Coli ◽  
Uv Visible

Silver nanoparticle (AgNP) was synthesized using the cell free extract of Scenedesmus abundans with AgNO3. The synthesized silver nanoparticles were characterized by UV-visible spectroscopy, dynamic light scattering (DLS), scanning electron microscopy (SEM), and Photoluminescence. Bioreduction of Ag+ ions showed a gradual change in the colour of the extract and nanoparticles were synthesized having the range of 420–440 nm under UV-visible spectrum. The antibacterial efficacy was assessed against pathogenic bacteria E. coli, Klebsiella pneumoniae, and Aeromonas hydrophila. The present study revealed that the AgNPs prepared from Scenedesmus abundans show antibacterial efficacy against the test pathogens. The bioaccumulation of silver particles makes the organism potential candidate for ecofriendly silver biorecovery system and S. abundans can be used as a source of silver nanoparticles.

scholarly journals Green synthesis of silver nanoparticles in aloe vera plant extract prepared by a hydrothermal method and their synergistic antibacterial activity

2016 ◽  
Author(s):  
Patcharaporn Tippayawat ◽  
Nutthakritta Phromviyo ◽  
Parichart Boueroy ◽  
Apiwat Chompoosor
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Green Synthesis ◽  
Hydrothermal Method ◽  
Plant Extract ◽  
Pathogenic Bacteria ◽  
Antibacterial Effect ◽  
Aloe Vera ◽  
Diffusion Method

Background: There is worldwide interest in silver nanoparticles (AgNPs) synthesized by various chemical reactions for use in applications exploiting their antibacterial activity, even though these processes exhibit a broad range of toxicity in vertebrates and invertebrates alike. To avoid the chemical toxicity, biosynthesis (green synthesis) of metal nanoparticles is proposed as a cost-effective and environmental friendly alternative. Aloe vera leaf extract is a medicinal agent with multiple properties including an antibacterial effect. Moreover the constituents of aloe vera leaves include lignin, hemicellulose, and pectins which can be used in the reduction of silver ions to produce as AgNPs@aloe vera (AgNPs@AV) with antibacterial activity. Methods: AgNPs were prepared by an eco-friendly hydrothermal method using an aloe vera plant extract solution as both a reducing and stabilizing agent. AgNPs@AV were characterized using XRD and SEM. Additionally, an agar well diffusion method was used to screen for antimicrobial activity. MIC and MBC were used to correlate the concentration of AgNPs@AV its bactericidal effect. SEM was used to investigate bacterial inactivation. Then the toxicity with human cells was investigated using an MTT assay. Results: The synthesized AgNPs were crystalline with sizes of 70.70 ± 22-192.02 ± 53 nm as revealed using XRD and SEM. The sizes of AgNPs can be varied through alteration of times and temperatures used in their synthesis. These AgNPs were investigated for potential use as an antibacterial agent to inhibit pathogenic bacteria. Their antibacterial activity was tested on S. epidermidis and P. aeruginosa. The results showed that AgNPs had a high antibacterial which depended on their synthesis conditions, particularly when processed at 100 oC for 6 h and 200 oC for 12 h. The cytotoxicity of AgNPs was determined using human PBMCs revealing no obvious cytotoxicity. These results indicated that AgNPs@AV can be effectively utilized in pharmaceutical, biotechnological and biomedical applications. Discussion: Aloe vera extract was processed using a green and facile method. This was a hydrothermal method to reduce silver nitrate to AgNPs@AV. Varying the hydrothermal temperature provided the fine spherical shaped nanoparticles. The size of the nanomaterial was affected by its thermal preparation. The particle size of AgNPs could be tuned by varying both time and temperature. A process using a pure AG phase could go to completion in 6h at 200 oC, whereas reactions at lower temperatures required longer times. Moreover, the antibacterial effect of this hybrid nanomaterial was sufficient that it could be used to inhibit pathogenic bacteria since silver release was dependent upon its particle size. The high activity of the largest AgNPs might have resulted from a high concentration of aloe vera compounds incorporated into the AgNPs during hydrothermal synthesis.

scholarly journals Green synthesis of silver nanoparticles in aloe vera plant extract prepared by a hydrothermal method and their synergistic antibacterial activity

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2589 ◽  
Author(s):  
Patcharaporn Tippayawat ◽  
Nutthakritta Phromviyo ◽  
Parichart Boueroy ◽  
Apiwat Chompoosor
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Green Synthesis ◽  
Hydrothermal Method ◽  
Plant Extract ◽  
Pathogenic Bacteria ◽  
Antibacterial Effect ◽  
Aloe Vera ◽  
Diffusion Method

BackgroundThere is worldwide interest in silver nanoparticles (AgNPs) synthesized by various chemical reactions for use in applications exploiting their antibacterial activity, even though these processes exhibit a broad range of toxicity in vertebrates and invertebrates alike. To avoid the chemical toxicity, biosynthesis (green synthesis) of metal nanoparticles is proposed as a cost-effective and environmental friendly alternative. Aloe vera leaf extract is a medicinal agent with multiple properties including an antibacterial effect. Moreover the constituents of aloe vera leaves include lignin, hemicellulose, and pectins which can be used in the reduction of silver ions to produce as AgNPs@aloe vera (AgNPs@AV) with antibacterial activity.MethodsAgNPs were prepared by an eco-friendly hydrothermal method using an aloe vera plant extract solution as both a reducing and stabilizing agent. AgNPs@AV were characterized using XRD and SEM. Additionally, an agar well diffusion method was used to screen for antimicrobial activity. MIC and MBC were used to correlate the concentration of AgNPs@AV its bactericidal effect. SEM was used to investigate bacterial inactivation. Then the toxicity with human cells was investigated using an MTT assay.ResultsThe synthesized AgNPs were crystalline with sizes of 70.70 ± 22-192.02 ± 53 nm as revealed using XRD and SEM. The sizes of AgNPs can be varied through alteration of times and temperatures used in their synthesis. These AgNPs were investigated for potential use as an antibacterial agent to inhibit pathogenic bacteria. Their antibacterial activity was tested onS. epidermidisandP. aeruginosa. The results showed that AgNPs had a high antibacterial which depended on their synthesis conditions, particularly when processed at 100oC for 6 h and 200oC for 12 h. The cytotoxicity of AgNPs was determined using human PBMCs revealing no obvious cytotoxicity. These results indicated that AgNPs@AV can be effectively utilized in pharmaceutical, biotechnological and biomedical applications.DiscussionAloe vera extract was processed using a green and facile method. This was a hydrothermal method to reduce silver nitrate to AgNPs@AV. Varying the hydrothermal temperature provided the fine spherical shaped nanoparticles. The size of the nanomaterial was affected by its thermal preparation. The particle size of AgNPs could be tuned by varying both time and temperature. A process using a pure AG phase could go to completion in 6 h at 200oC, whereas reactions at lower temperatures required longer times. Moreover, the antibacterial effect of this hybrid nanomaterial was sufficient that it could be used to inhibit pathogenic bacteria since silver release was dependent upon its particle size. The high activity of the largest AgNPs might have resulted from a high concentration of aloe vera compounds incorporated into the AgNPs during hydrothermal synthesis.

scholarly journals ANTIBACTERIAL AND ANTICANCER POTENTIAL OF SILVER NANOPARTICLES SYNTHESIZED USING GALLIC ACID IN BENTONITE/STARCH BIO-NANOCOMPOSITES

2018 ◽  
Vol 10 (5) ◽  
pp. 178 ◽  
Author(s):  
Anupama Thapliyal ◽  
Amrish Chandra
Keyword(s):  
Silver Nanoparticles ◽  
Zeta Potential ◽  
Gallic Acid ◽  
Cell Line ◽  
Cancer Cell ◽  
Low Cost ◽  
Cancer Cell Line ◽  
Diffusion Method ◽  
Potential Candidate ◽  
Mcf 7

Objective: To optimize and synthesize eco-friendly and low-cost silver nanoparticles (AgNPs) by using gallic acid (GA) reducing agent in bentonite/starch bio-nanocomposites (BNCs) for oral use and to evaluate its antibacterial and anticancer efficacy.Methods: An artificial neural network (ANN) model was employed for the optimization and evaluate the effect of the formulation variables on the entrapment efficiency (EE) of AgNPs. The synthesized AgNPs in BNCs were characterized using UV-vis spectroscopy, energy dispersive X-ray spectroscopy (EDXA), dynamic light scattering (DLS), scanning electron microscopy (SEM), zeta potential and fourier transform infrared spectroscopy (FTIR). Elemental ion analysis was carried out using inductively coupled plasma mass spectrometry (ICP-MS). Drug release study was carried out. The antimicrobial efficacy determined by agar well diffusion method. In vitro anticancer efficacy of AgNPs in breast cancer cell line (MCF-7) by MTT assay was performed.Results: The formation of AgNPs was confirmed by UV-vis absorbance peak shown at 412 nm. XRD spectrum has indicated the face-centered cubic structure of the synthesized AgNPs. SEM and DLS measurements showed spherical nanoparticles with a mean size of 68.06±0.2 nm. The negative surface zeta potential with-32±0.25 mV has indicated colloidal stability of nanoparticles. FTIR spectra confirmed no interaction observed between drug and excipients. AgNPs showed significant EE with 80±0.25%. The synthesized AgNPs in BNCs is a potential candidate for inhibiting the growth of pathogenic bacteria and showed significant cytotoxicity against MCF-7 cancer cell line with IC50 of 160±0.014μg/ml.Conclusion: The present research confirms that the green synthesized AgNPs in BNCs can be a promising antibacterial and anticancer agent regarding stability, low cost and easy preparation.

scholarly journals Herbal Plant Synthesis of Antibacterial Silver Nanoparticles by Solanum trilobatum and Its Characterization

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
M. Vanaja ◽  
K. Paulkumar ◽  
G. Gnanajobitha ◽  
S. Rajeshkumar ◽  
C. Malarkodi ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Electron Microscope ◽  
Green Synthesis ◽  
Pathogenic Bacteria ◽  
Diffusion Method ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Solanum Trilobatum ◽  
Green Synthesized Silver Nanoparticles

Green synthesis method of nanomaterials is rapidly growing in the nanotechnology field; it replaces the use of toxic chemicals and time consumption. In this present investigation we report the green synthesis of silver nanoparticles (AgNPs) by using the leaf extract of medicinally valuable plant Solanum trilobatum. The influence of physical and chemical parameters on the silver nanoparticle fabrication such as incubation time, silver nitrate concentration, pH, and temperature is also studied in this present context. The green synthesized silver nanoparticles were characterized by UV-vis spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray (EDX), and transmission electron microscope (TEM). The SEM and TEM confirm the synthesis of spherical shape of nanocrystalline particles with the size range of 2–10 nm. FTIR reveals that the carboxyl and amine groups may be involved in the reduction of silver ions to silver nanoparticles. Antibacterial activity of synthesized silver nanoparticles was done by agar well diffusion method against different pathogenic bacteria. The green synthesized silver nanoparticles can be used in the field of medicine, due to their high antibacterial activity.

Preliminary in Vitro Investigations on The Inhibitory Activity of The Original Dietary Supplement Oxidal® on Pathogenic Bacterial Strains

2020 ◽  
Vol 11 ◽  
pp. 37-43
Author(s):  
Prof. Teodora P. Popova ◽  
Toshka Petrova ◽  
Ignat Ignatov ◽  
Stoil Karadzhov
Keyword(s):  
Dietary Supplement ◽  
Broad Spectrum ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Clinical Effectiveness ◽  
Inhibitory Effect ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Microbial Strains

The antimicrobial action of the dietary supplement Oxidal® was tested using the classic Bauer and Kirby agar-gel diffusion method. Clinical and reference strains of Staphylococcus aureus and Escherichia coli were used in the studies. The tested dietary supplement showed a well-pronounced inhibitory effect against the microbial strains commensurable with that of the broad-spectrum chemotherapeutic agent Enrofloxacin and showed even higher activity than the broad spectrum antibiotic Thiamphenicol. The proven inhibitory effect of the tested dietary supplement against the examined pathogenic bacteria is in accordance with the established clinical effectiveness standards for antimicrobial agents.

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