Fabrication Of Silver Nanoparticles Research Articles

Assessment of Silver Nanoparticles Derived from Brown Algae Sargassum vulgare: Insight into Antioxidants, Anticancer, Antibacterial and Hepatoprotective Effect.

Algae are used as safe materials to fabricate novel nanoparticles to treat some diseases. Marine brown alga Sargassum vulgare are used to fabricate silver nanoparticles (Sv/Ag-NPs). The characterization of Sv/Ag-NPs was determined by TEM, EDX, Zeta potential, XRD, and UV spectroscopy. The Sv/Ag-NPs were investigated as antioxidant, anticancer, and antibacterial activities against Gram-positive bacteria Bacillus mojavensis PP400982, Staphylococcus caprae PP401704, Staphylococcus capitis PP402689, and Staphylococcus epidermidis PP403851. The activity of the Sv/Ag-NPs was evaluated as hepatoprotective in vitro in comparison with silymarin. The UV-visible spectrum of Sv/Ag-NPs appeared at 442 nm; the size of Sv/Ag-NPs is in range between 6.90 to 16.97 nm, and spherical in shape. Different concentrations of Sv/Ag-NPs possessed antioxidant, anticancer activities against (HepG-2), colon carcinoma (HCT-116), cervical carcinoma (HeLa), and prostate carcinoma (PC-3) with IC50 50.46, 45.84, 78.42, and 100.39 µg/mL, respectively. The Sv/Ag-NPs induced the cell viability of Hep G2 cells and hepatocytes treated with carbon tetrachloride. The Sv/Ag-NPs exhibited antibacterial activities against Staphylococcus caprae PP401704, Staphylococcus capitis PP402689, and Staphylococcus epidermidis PP403851. This study strongly suggests the silver nanoparticles derived from Sargassum vulgare showed potential hepato-protective effect against carbon tetrachloride-induced liver cells, and could be used as anticancer and antibacterial activities.

Investigation of Antimicrobial Activity and Cytotoxicity of Silver Nanoparticle Synthesized using Dopamine as a Reducing and Capping Agent

AbstractWe present a study focused on the controlled fabrication of silver nanoparticles (AgNPs) through colloidal synthesis, employing dopamine as a reducing and capping agent. By manipulating the concentration of silver nitrate, the production of spherical AgNPs with distinct particle diameters (16, 24, 48, and 74 nm) was achieved. The investigation extended to the evaluation of AgNPs′ impact on human embryonic kidney cells, revealing a concentration‐dependent response. At lower AgNPs concentrations, cell viability remained nearly 100 %, progressively declining with rising AgNPs concentrations. Importantly, the cytotoxic thresholds observed were notably elevated, underscoring the relatively mild to moderate toxicity profile of the nanoparticles. Furthermore, the antimicrobial efficacy of these synthesized AgNPs was probed against E. coli and S. aureus bacterial strains. Notably, the AgNPs exhibited robust antimicrobial activity, with superior performance exhibited by smaller‐sized particles compared to larger ones. Impressively, the minimum inhibitory concentration reached as low as 3.5 μg/mL, indicating their potent antimicrobial potential. The achieved distinct particle diameters, concentration‐dependent cytotoxic responses, and potent antimicrobial efficacy against bacterial strains underscore the multifaceted potential of these nanoparticles. These findings contribute valuable insights for their application in diverse fields, from biomedicine to antimicrobial solutions.

Simultaneous enhancements on emissions from quantum dot and quantum well by Ag nanoparticles for color conversion

Quantum dots (QDs) have been paid much attention on the color conversion for light-emitting diode (LED) in micro-display recently. However, it is hard to achieve high color conversion efficiency in a thin QD layer. In this paper, we fabricated silver nanoparticles (Ag NPs) with radii ranging mostly from 25 to 35 nm on a blue LED with a peak wavelength of 450 nm, then spin-coated QDs with a peak wavelength of 565 nm. Scanning electron microscopy, cathodoluminescence, photoluminescence (PL), and time-resolved PL measurements were performed. The PL emissions from quantum wells (QWs) of blue LED and QDs were enhanced by 10% and 32%, respectively, when the Ag NPs were included. The PL lifetimes of QWs and QDs were reduced by 10 and 6 times, respectively, compared to their initial states. Finite difference time domain software and the perturbation method were used to simulate the PL measurements and variable separation. It was concluded that the coupling of QDs and QWs with localized surface plasmon improves the external quantum efficiency and enhances the spontaneous emission rate in both QWs and QDs. This paper provides a new idea for designing high-efficiency color conversion micro-LED.

Exploring the biological properties of Saccharomyces cerevisiae-derived silver nanoparticles: In vitro structural characteristics, antibacterial, biofilm inhibition and biofilm degradation, antioxidant, anticoagulant, thrombolytic, and antidiabetic performance

In the present study, Saccharomyces cerevisiae was employed to fabricate silver nanoparticles (AgNPs) as a sustainable and ecofriendly approach. The mycofabricated AgNPs were found to be spherical with a Z-average size of 29.07 nm and zeta potential of −16 mV. This study focused on the biological properties of fungus-mediated fabrication of AgNPs. The AgNPs ascertained significant antibacterial activity against Listeria monocytogenes and Serratia marcescens with minimum inhibitory concentration (MIC) of 4 and 2 µg mL−1 and minimum bactericidal concentration (MBC) of 16 and 16 µg mL−1, respectively. Besides, the AgNPs at the studied concentrations ascertained significantly higher biofilm inhibitory and degradation activity against S. marcescens compared to the reference antibiotic drug gentamicin (P < 0.05). In contrast, gentamicin at the studied concentrations exhibited significantly higher biofilm inhibitory and degradation activity against L. monocytogenes compared to AgNPs (P < 0.05). Moreover, Flow cytometry analysis exhibited dose-dependent antibacterial properties for both AgNPs and gentamicin against both S. marcescens and L. monocytogenes. Furthermore, the AgNPs ascertained a dose-dependent antioxidant activity with a maximum 65.75 ± 2.70 % at the concentration of 500 µg mL−1. Impressively, the AgNPs at the concentration of 500 µg mL−1 represented anticoagulant performance with PT and aPTT values of 21.80 ± 3.31 and 70.57 ± 2.25 s, respectively. Additionally, the AgNPs at the concentration of 500 µg mL−1 showed 19.48 ± 3.82 % thrombolysis and 64.74 ± 1.63 % alpha-amylase inhibition. The AgNPs also ascertained a maximum 38.26 ± 1.70 % glucose uptake inhibition by S. cerevisiae at a concentration of 1000 µg mL−1. Overall, the above-mentioned unique physicochemical and biological properties of AgNPs made them attractive for biomedicine.

Eco-Friendly Fabrication of Silver Nanoparticles for Sustainable Water Purification and Antibacterial Synergy

Eco-Friendly Fabrication of Silver Nanoparticles for Sustainable Water Purification and Antibacterial Synergy

Potent biological activity of newly fabricated silver nanoparticles coated by a carbon shell synthesized by electrical arc

Highly effective AgNPs@C was efficiently synthesized by electrical arc powered by single spark unit which was sufficient to ionize the dielectric media (deionized water) through applying strong electric field between the electrodes (silver and carbon). The AgNPs@C shell was characterized in terms of stability, morphology and phase structure. All characterizations showed that the prepared silver nanoparticles were spherical with average size reached 17 nm coated with carbon shell. The antibacterial effect of the synthesized nanoparticles was tested against Pseudomonas aeruginosa in comparison to Ceftazidime (commonly used antibiotic against P. aeruginosa infections). It was revealed that AgNPs@C shell has superior activity with inhibition zone diameter reached 15 mm and minimum inhibitory concentration reached 2 µg/mL. The observed activity was further confirmed by confocal microscope which showed an increased red region, representing the dead cells, correlated with the presence of AgNPs@C. Moreover, transmission electron microscope studies implied the possible AgNPs@C antibacterial mechanism of action was the nanoparticles adherence to the bacterial membrane causing cell lysis. The molecular studies against fimH (virulence adhesion gene), rmpA (mucoid factor encoding gene), and mrkA (biofilm forming gene) proved the inhibition of their genetic expression. The cytotoxic effect of the synthesized AgNPs@C showed CC50 reached 235.5 μg/mL against normal lung cells (L929 cell line).

Exploring the Antimicrobial, Antioxidant, and Antiviral Potential of Eco-Friendly Synthesized Silver Nanoparticles Using Leaf Aqueous Extract of Portulaca oleracea L.

Herein, the prospective applications of green fabricated silver nanoparticles (Ag-NPs) within the biomedical field were investigated. The leaf aqueous extract of Portulaca oleracea L., a safe, cheap, and green method, was used to fabricate Ag-NPs. The maximum plasmon resonance of synthesized NPs has appeared at 420 nm. The various biomolecules present in the plant extract to assemble spherical Ag-NPs with sizes of 5-40 nm were analyzed using Fourier transform infrared and transmission electron microscopy. The Ag was the major content of the formed Ag-NPs with an atomic percent of 54.95% and weight percent of 65.86%, as indicated by EDX. The crystallographic structure of synthesized NPs was confirmed by the diffraction of the X-ray. The dynamic light scattering exhibits the homogeneity and mono-dispersity nature with a polydispersity index of 0.37 in the colloidal fluid and a zeta potential value of -36 mV. The synthesized Ag-NPs exhibited promising antimicrobial efficacy toward various prokaryotic and eukaryotic pathogenic microorganisms with low MIC values of 12.5 µg mL-1 and 6.25 µg mL-1, respectively. Additionally, the P. oleracea-formed Ag-NPs showed optimistic antioxidant activity assessed by DPPH and H2O2 assay methods with the highest scavenging percentages of 88.5 ± 2.3% and 76.5 ± 1.7%, respectively, at a concentration of 200 µg mL-1. Finally, the biosynthesized Ag-NPs showed high antiviral properties toward the hepatitis A virus and Cox-B4 with inhibition percentages of 79.16 ± 0.5% and 73.59 ± 0.8%, respectively. Overall, additional research is essential to explore the Ag-NP-based aqueous extract of P. oleracea for human health. In the current investigation the use of synthesized Ag-NPs as antimicrobial, antioxidant, and antiviral agents to protect against pathogenic microbes, degenerative diseases caused by various oxidative stresses, and deadly viruses is recommended.

Fabrication of Silver Nanoparticle Loaded into Nanocellulose Derived from Hemp and Poly(vinyl alcohol)-Based Composite as an Electrode for Electrochemical Sensors for Lactate Determination.

Nanocellulose derived from hemp (HNC) with the addition of silver nanoparticles (AgNPs) is utilized for improving the electrochemical sensing performances for lactate detection. Initially, HNC is chemically extracted and purified by using alkali treatment and acid hydrolysis. Then, AgNPs are nucleated in situ by the self-reduction process prior to forming a composite with poly(vinyl alcohol) (PVA). This nanocomposite significantly improves the electrochemical properties of the electrode, including electrochemical conductivity and electrocatalysis. The morphologies and chemical alterations of the HNC/AgNPs-PVA nanocomposite are investigated by field emission scanning electron microscopy. It demonstrates a three-dimensional network with random orientation of the nanocellulose fiber. The AgNPs are well-dispersed in the nanocomposite. Moreover, the nanocomposite provides high thermal stability up to 450 °C. Then, it is remarkably noted that 10 wt % HNC/AgNPs-PVA modified on the electrode provides the highest current responses, with a standard redox couple [(Fe(CN)6]3-/4-]. For lactate detection, this modified screen-printed graphene electrode with nonimmobilized lactate oxidase exhibits an increase in the current signal with the increment of lactate concentration and offered a linear range of 0-25 mM, covering a cutoff value (12.5 mM) for muscle fatigue indication. Eventually, this sensor is successfully applied for lactate detection with high potential for a wearable lactate sensor.

Streptomyces pratensis-Mediated Fabrication of Silver Nanoparticles and Its Applications as Antimicrobial and Anticancer

Streptomyces pratensis-Mediated Fabrication of Silver Nanoparticles and Its Applications as Antimicrobial and Anticancer

Green fabrication of silver nanoparticles using leaf extract of tropical vine Momordica charantia: spectral characterization and in vitro cytotoxicity evaluation on human breast cancer cells

ABSTRACT The use of environmental materials such as plant extract for the synthesis of silver nanoparticles (AgNPs) offers numerous benefits of eco-friendliness and compatibility for pharmaceutical and other biomedical Applications. In this study, we used Momordica charantia leaf extract as a reducing agent for the synthesis of AgNPs. Characterization of the AgNPs was done by UV-Visible Spectroscopy, FTIR, SEM, TEM and EDX. Furthermore, we established the in vitro anticancer efficacy of these nanoparticles against the human breast cancer cell line MCF-7 using MTT assay, nuclear morphology testing, and staining. In addition to the above, the anti-bacterial effect was also tested against a range of bacterial isolates using well-diffusion method. These AgNPs also demonstrated impressive results when tested for their free-radical scavenging efficiency on the MCF-7 breast cancer cell line, indicating future potential for their use in medicine. These findings indicated the possible applicability of biosynthesized AgNPs derived from Momordica charantia L.

Green fabrication of silver nanoparticles and it’s in vitro anti-bacterial, anti-biofilm, free radical scavenging and mushroom tyrosinase efficacy evaluation

This paper reports a fast, reliable, and efficient protocol for the synthesis of silver nanoparticles using the medicinal plant Paeonia Japonica (PJ) root extract and the in-vitro biological activities of the synthesized AgNPs. The results of XRD and TEM analysis showed that the particles are in 28 nm size with spherical morphology. The PJ–AgNPs portrayed excellent anti-bacterial activity against the gram (+ve) and (−ve) microorganism studied in dose dependent manner. It exhibits very good anti-biofilm activity against the pathogenic S. Aureus with respect to the dose used (89 % inhibition at 100 µg/mL dose). Further it has the ability to scavenge the DPPH free radical efficiently (96.5 % scavenging at 200 µg/mL dose). Added to this the synthesized PJ-AgNPs displayed a very good mushroom tyrosinase inhibition at the tested concentrations. The above results indicate the potential of silver nanoparticles synthesized using PJ root extract can be used as an antibacterial, anti-biofilm, anti-oxidant, enzyme inhibitor in the food, medical and cosmetic industry.

Microwave-accelerated heating technique in fabrication of silver nanoparticles using propolis extract: optimization and characterization

Abstract Silver nanoparticle (AgNPs) is known as a new generation of antibiotics with high bactericidal activity and resistance toward numerous bacteria strains. In the present study, AgNPs were synthesized using propolis extract and microwave heating technique. Results indicated that, the prepared hydroalcoholic propolis extract had brix, turbidity, total phenol content and antioxidant activity of 5.21° Bx, 1.75 % a.u., 82.52 mg/g (gallic acid) and 93.32 %, respectively. FTIR analysis also indicated that the prepared extract had several main functional groups such as hydroxyl, carboxyl, amide I, amin and esters, which those could act as reducing and stabilizing agents in fabrication of stable AgNPs. Furthermore, GC-MS analysis demonstrated that alpha-terpinene, coumaran, p-methoxycinnamic acid, dimethyl caffeic acid and pinostrobin chalcone were the main bioactive compounds of the prepared propolis extract. Results revealed that AgNPs with small particle size (86 nm) and polydespersity index (0.299), and high zeta potential (−23.34) values could be synthesized using 0.1 mL of the extract in combination to 9 mL silver nitrate (1 mM) under microwave heating for 30 s. TEM analysis demonstrated that spherical fabricated AgNPs had uniform particle size distribution with particle size of less than 100 nm. Finally, synthesized AgNps indicated higher bactericidal activity against Listeria monocytogenes and Escherichia coli, with obtained clear zone diameter of 22 and 19 mm, respectively.

Fabrication of silver nanoparticles loaded acacia gum/chitosan nanogel to coat the pipe surface for sustainable inhibiting microbial adhesion and biofilm growth in water distribution systems

Biofilm formation on the inner surfaces of pipes poses significant threats to water distribution systems, increasing maintenance costs and public health risks. To address this immense issue, we synthesized a nanogel formulation comprising acacia gum (AG) and chitosan (Cs), loaded with varying concentrations of silver nanoparticles (AgNPs), for using as an antimicrobial coating material. AgNPs were synthesized using AG as a reducing and stabilizing agent, exhibiting absorbance at 414 nm. The preparation of AgNPs was proved using TEM. Bactericidal efficacy was assessed against E. coli, Klebsiella pneumoniae, Enterococcus faecalis, and Bacillus subtilis. Using the dipping coating method, two pipe materials (polypropylene (PP) and ductile iron (DI)) were successfully coated. Notably, AgNPs2@AGCsNG nanogel exhibited potent antibacterial action against a wide range of pathogenic bacteria. Toxicity tests confirmed nanogel safety, suggesting broad applications. High EC50% values underscored their non-toxic nature. This research proposes an effective strategy for biofilm prevention in water systems, offering excellent antibacterial properties and biocompatibility. AG and Cs nanogels loaded with AgNPs promise to enhance water quality, reduce maintenance prices, and protect human public health in water distribution networks.

Antibacterial, antioxidant, and anticancer potential of green fabricated silver nanoparticles made from Viburnum grandiflorum leaf extract

BackgroundRecently, researchers are focusing on creating new tools to combat the antibiotic resistant bacteria and malignancy issues, which pose significant threats to humanity. Biosynthesized silver nanoparticles (AgNPs) are thought to be a potential solution to these issues. The biosynthesis method, known for its environmentally friendly and cost-effective characteristics, can produce small-sized AgNPs with antimicrobial and anticancer properties. In this study, AgNPs were bio-fabricated from the distilled water and methanolic extracts of Viburnum grandiflorum leaves. Physio-chemical characterization of the bio-fabricated AgNPs was conducted using UV-visible spectroscopy, scanning electron microscopy, energy dispersive X-ray, and X-ray diffraction analysis.ResultsAgNPs produced from the methanol extract were smaller in size (12.28 nm) compared to those from the aqueous extract (17.77 nm). The bioengineered AgNPs exhibited a circular shape with a crystalline nature. These biosynthesized AgNPs demonstrated excellent bactericidal activity against both gram-negative (Pseudomonas aeruginosa) and gram-positive (Staphylococcus aureus) bacteria. Highest antibacterial activity was observed with the methanol extract against P. aeruginosa (14.66 ± 0.74 mm). AgNPs from the methanol extract also displayed the highest antioxidant activity, with an IC50 value of 188.00 ± 2.67 μg/mL against 2,2-diphenyl-1-picrylhydrazyl (DPPH). Furthermore, AgNPs exhibited notable cytotoxic activity against Rhabdomyosarcoma cell line (RD cell) of human muscle cancer cell. The IC50 values calculated from the MTT assay were 26.28 ± 1.58 and 21.49 ± 1.44 μg/mL for AgNPs synthesized from aqueous and methanol extracts, respectively.ConclusionThe methanol extract of V. grandiflorum leaves demonstrates significant potential for synthesizing AgNPs with effective antibacterial, antioxidant, and anticancer actions, making them applicable in various biomedical applications.

Synthesis of silver nanoparticles using Alchemilla vulgaris and Helichrysum arenarium for methylene blue and 4-nitrophenol degradation and antibacterial applications

AbstractThis study aimed to evaluate the concept of green synthesis of metallic nanoparticles (silver nanoparticles, AgNPs) by plant extracts without using any toxic or hazardous materials. Alchemilla vulgaris (AV) and Helichrysum arenarium (HA) are used as capping and reducing agents to synthesize AgNPs (as coded AV-AgNPs and HA-AgNPs). Both synthesized AgNPs were characterized by UV–visible spectrophotometry, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and transmission electron microscope (TEM). The results of characterization exhibited that AgNPs were successfully synthesized. They are highly well-dispersed, mostly spherical shape with an average size 15–20 nm. Catalytic reduction of methylene blue (MB) and 4-nitrophenol (4-NP) was assessed using synthesized AgNPs as nano-catalysts in the presence of NaBH4. The catalytic activity of the synthesized AgNPs revealed significant results in terms of degradation of MB and 4-NP to 4-AP (4-aminophenol). The reduction reactions of MB and 4-NP happen within 6–7 min using synthesized AV-AgNPs and HA-AgNPs in the presence of NaBH4. According to the reusability analysis, synthesized AgNPs demonstrated excellent degradation performances by the more than 94% removal efficiency maintained after five reuse cycles. In addition, antibacterial activities of AgNPs were investigated against Escherichia coli (E. coli; Gram-negative bacteria) and Staphylococcus aureus (S. aureus; Gram-positive bacteria) by using quantitative well-diffusion method and the inhibition zones were determined using Mueller–Hinton agar (MHA) media. AV-AgNPs and HA-AgNPs showed strong antibacterial activities against E. coli with in inhibition zone diameters 25.5 and 25 mm, respectively. AV-AgNPs and HA-AgNPs were also extremely effective on S. aureus with high inhibition zone values of 22 and 24 mm, respectively. Finally, the fabricated silver nanoparticles could be excellent candidates for the separation of hazardous materials.

Green synthesized silver nanoparticles (AgNPs) using aqueous extract of &lt;i&gt;Calotropis procera&lt;/i&gt; and its antimicrobial activity on clinical bacteria isolates

The green synthesis of nanoparticles, utilizing aqueous plant extract as a capping and stabilizing agent, has attracted significant attention in various domains, particularly in pharmaceuticals and drug delivery. In this investigation, silver nitrate (AgNO3) salts were employed as precursors to fabricate silver nanoparticles using Calotropis procera (leaves/flower) extract, and the resulting nanoparticles were characterized. Fourier Transform Infrared (FTIR) spectroscopy revealed three primary functional groups at peaks of 2851.4 cm-1, 1543.1 cm-1, and 1323.2 cm-1, responsible for capping and stabilizing the synthesized C.p-AgNPs. Scanning Electron Microscopy (SEM) demonstrated that the synthesized C.p-AgNPs exhibited spherical shapes with an average particle size ranging from 20 nm to 30 nm. Energy-dispersive X-ray (EDX) analysis of the synthesized C.p-AgNPs indicated the presence of pure silver (Ag) at 54.32% in the region of 2.7 to 3.1 keV. Furthermore, the antimicrobial activity of C.p-AgNPs was examined, with the best inhibition observed at 0.5 mg/mL on Gram-negative bacteria S. aureus (12.0 mm) and Streptococcus spp (13.0 mm), and on Gram-positive bacteria E. coli (16.0 mm) and Salmonella spp (14.0 mm). The antimicrobial efficacy was dose-dependent, suggesting the potential for eradicating resistant human pathogenic bacteria. The antibacterial potential of C.p-AgNPs could be enhanced by increasing their concentration, depending on the specific application. Based on the study's findings, C.p-AgNPs derived from Calotropis procera can be employed for various biomedical purposes, such as textile coating by incorporating C.p-AgNPs in fibers and food storage by nanocapsulation of food items to extend their shelf life.

Biogenic synthesis of silver nanoparticles using Rubus fruticosus extract and their antibacterial efficacy against Erwinia caratovora and Ralstonia solanacearum phytopathogens.

In the current research, we produced green, cost-effective, eco-friendly silver nanoparticles using a single-step approach. Plants are considered highly desirable systems for nanoparticle synthesis because they possess a variety of secondary metabolites with significant reduction potential. In the current research, the dried leaf extract of Rubus fruticosus was utilized as a capping and reducing agent for the fabrication of silver nanoparticles, to prepare reliable biogenic silver nanoparticles and subsequently to investigate their potential against some common phytopathogens. The prepared silver nanoparticles were exploited to quantify the total flavonoid content (TFC), total phenolic content (TPC) and DPPH-based antioxidant activity. Different concentrations of aqueous extracts of plant leaves and silver nitrate (AgNO3) were reacted, and the color change of the reactant mixture confirmed the formation of Rubus fruticosus leaf-mediated silver nanoparticles (RFL-AgNPs). A series of characterization techniques such as UV-vis spectroscopy, transmission electron microscopy, energy dispersive X-ray analysis and X-ray diffraction revealed the successful synthesis of silver nanoparticles. The surface plasmon resonance peak appeared at 449 nm. XRD analysis demonstrated the crystalline nature, EDX confirmed the purity, and TEM demonstrated that the nanoparticles are mostly spherical in form. Furthermore, the biosynthesized nanoparticles were screened for in vitro antibacterial activity, antioxidant activity, and total phenolic and flavonoid content. The nanoparticles were used in different concentrations alone and in combination with plant extracts to inhibit Erwinia caratovora and Ralstonia solanacearum. In high-throughput assays used to inhibit these plant pathogens, the nanoparticles were highly toxic against bacterial pathogens. This study can be exploited for planta assays against phytopathogens utilizing the same formulations for nanoparticle synthesis and to develop potent antibacterial agents to combat plant diseases.

Bacteria against bacteria: Green silver nanoparticle fabrication, antioxidant, anti-biofilm and antibacterial activities

Bacteria against bacteria: Green silver nanoparticle fabrication, antioxidant, anti-biofilm and antibacterial activities

Green synthesized AgNPs, CuONPs, and Ag‐CuO NCs to effective antibiofilm activities and their potential application in aquaculture

The expanded emergence of drug‐resistant microbes remains a concern to the scientific community in developing effective therapeutics. Approach of green chemistry based nanomaterials fabrication is in high demand, due to biocompatibility, non‐toxic, and high surface area that adheres more biomolecules on surface. Green fabricated silver nanoparticles (AgNPs), copper oxide nanoparticles (CuONPs), and silver–copper oxide nanocomposites (Ag‐CuO NCs) were characterized by fluorescence and Raman spectroscopy, field emission scanning electron microscopy (FE‐SEM) with energy‐dispersive X‐ray spectroscopy (EDX), and thermogravimetric (TG)/differential scanning calorimetry (DSC) analysis. Antibiofilm potential of green fabricated AgNPs, CuONPs, and Ag‐CuO NCs was tested against aquatic pathogenic microorganisms such as Aeromonas hydrophila, Pseudomonas aeruginosa, and Staphylococcus aureus. This present study deals with bacterial growth rate, biofilm inhibition, and antibiofilm architecture of AgNPs, CuONPs, and Ag‐CuO NCs under the visualization of confocal laser scanning electron microscopy (CLSM). The FE‐SEM technique was used to observe dense and compact structure (control without NPs treatment) with treatment of NPs that showed reduced amount of cell population in A. hydrophila, P. aeruginosa, and S. aureus. The effective antibiofilm inhibition of Ag‐CuO NCs was achieved by reducing micro‐colonies compared with AgNPs and CuONPs. The AgNPs, CuONPs, and Ag‐CuO NCs demonstrated antibiofilm properties against Gram‐negative and Gram‐positive bacteria, indicating a combinatorial effect of green fabricated NPs in combination with plant metabolites against pathogenic bacteria. As a result, aforementioned nano‐product merits further investigation in order to be used as a potent adjuvant therapy as antagonistic toward various bacterial diseases in aquaculture.

Plant mediated fabrication of silver nanoparticles, process optimization, and impact on tomato plant

Nanotechnology is one of the fastest-growing markets, but developing eco-friendly products, their maximum production, stability, and higher yield is a challenge. In this study, silver nanoparticles were synthesized using an easily available resource, leaves extract of the Neem (Azadirachta indica) plant, as a reducing and capping agent, determined their effect on germination and growth of tomato plants. The maximum production of silver nanoparticles was noted at 70 °C after 3 h of reaction time while treating the 10 ml leaf extract of Neem plant with 10 ml of 1 mM silver nitrate. The impact of the extract preparation method and solvent type on the plant mediated fabrication of silver nanoparticles was also investigated. The UV-spectrophotometric analysis confirmed the synthesis of silver nanoparticles and showed an absorption spectrum within Δ420–440 nm range. The size of the fabricated silver nanoparticles was 22–30 nm. The functional groups such as ethylene, amide, carbonyl, methoxy, alcohol, and phenol attached to stabilize the nanoparticles were observed using the FTIR technique. SEM, EDX, and XRD analyses were performed to study the physiochemical characteristics of synthesized nanoparticles. Silver nanoparticles increased the germination rate of tomato seeds up to 70% while decreasing the mean germination time compared to the control. Silver nanoparticles applied at varying concentrations significantly increased the shoot length (25 to 80%), root length (10 to 60%), and fresh biomass (10 to 80%) biomass of the tomato plant. The production of total chlorophyll, carotenoid, flavonoids, soluble sugar, and protein was significantly increased in tomato plants treated with 5 and 10 ppm silver nanoparticles compared to the control. Green synthesized silver nanoparticles are cost-effective and nontoxic and can be applied in agriculture, biomedical, and other fields.