Eco-friendly Synthesis Of Silver Nanoparticles Research Articles

Eco-friendly synthesis of silver nanoparticles: unraveling their influence on callus proliferation, secondary metabolite production, and antioxidant activities in Ruta chalepensis L.

Eco-friendly synthesis of silver nanoparticles: unraveling their influence on callus proliferation, secondary metabolite production, and antioxidant activities in Ruta chalepensis L.

Gum karaya polymer-based biodegradable silver nanocomposite hydrogel through green approach for photocatalytic dye degradation and antimicrobial activity

The rise in industrialization and population growth has elevated water pollution to a critical environmental concern. This study introduces a novel polymer-mediated silver nanocomposite hydrogel for antibacterial activity and photocatalytic dye degradation for environmental remediation. In this study, silver nanocomposite hydrogels were developed using Karaya gum (KG), acrylamide, N-isopropyl acrylamide (NI), and 2-Bismethacryloyloxy ethyl phosphate (BMEP) as a crosslinker through a radical polymerization process. These hydrogels were utilized as templates for the eco-friendly synthesis of silver nanoparticles by employing an aqueous Canthium leaf extract as a reducing and stabilizing agent. Various analytical methods, including FTIR, UV–Vis, XPS, FESEM, EDX, XRD, AFM, and HRTEM, are characterized by the green synthesized KG-NIB-Ag nanocomposite hydrogel. Evaluation of the KG-NIB-Ag hydrogel involved examining its chemical composition, morphology, size, crystallinity, surface properties, bandgap, and chemical purity. TEM analysis validated an average crystallite size 33.2 nm. Moreover, the photocatalytic performance of the green-synthesized KG-NIB-Ag nanocomposite hydrogel was utilized to examine the degradation of Congo red dye under visible light irradiation. The findings of this study demonstrate that the degradation efficiency of CR reached approximately 73.25 % within 90 min, with a corresponding kinetic rate constant of 0.032 min−1. Furthermore, the antibacterial efficacy of the Ag nanocomposite hydrogel was evaluated against both Staphylococcus aureus and Escherichia coli. The disc diffusion method was employed to assess its antibacterial activity, and the diameter of the inhibition zones was measured. This study introduces an innovative and influential strategy for environmental remediation, emphasizing the potential of KG-NIB-Ag nanocomposite hydrogel in tackling ecological challenges associated with wastewater treatment across various industries.

Green synthesis approach: Utilizing chrysanthemum extract as reducing and stabilizing agent for the fabrication of silver nanoparticles and their antimicrobial properties study

This research explores the eco-friendly synthesis of silver nanoparticles (AgNPs) using Chrysanthemum extract, emphasizing its application in antimicrobial treatments. The study primarily focused on assessing the effect of extract concentration on nanoparticle characteristics. The synthesized AgNPs, at higher Chrysanthemum extract concentrations (up to 15%), exhibited a notable decrease in size, from 48.5 nm at 2% to 22.1 nm, and an increase in yield, achieving 2.24 mg/mL. The AgNPs showed a significant antibacterial effect, with the lowest IC50 value of 2.08 µg/mL against Vibrio cholerae, demonstrating a broad-spectrum efficacy. Advanced characterization techniques like SEM and FTIR spectroscopy confirmed the morphological integrity and phytochemical capping of the nanoparticles. The study successfully highlights the potential of Chrysanthemum extract not only as a sustainable source for nanoparticle synthesis but also in enhancing the biocompatibility and efficacy of AgNPs, paving the way for their application in medical and environmental fields.

Phyto-Fabrication of Moringa Oleifera Peel-Sourced Silver Nanoparticles: A Promising Approach for Combating Hepatic Cancer by Targeting Proinflammatory Cytokines and Mitigating Cytokine Storms.

Hepatocellular carcinoma (HCC) arises from precancerous nodules, leading to liver damage and inflammation, which triggers the release of proinflammatory cytokines. Dysregulation of these cytokines can escalate into a cytokine storm, causing severe organ damage. Interestingly, Moringa oleifera (M. oleifera) fruit peel, previously discarded as waste, contains an abundance of essential biomolecules and high nutritional value. This study focuses on the eco-friendly synthesis of silver nanoparticles infused with M. oleifera peel extract biomolecules and their impact on regulating proinflammatory cytokines, as well as their potential anticancer effects against Wistar rats. The freshly synthesized nanoformulation underwent comprehensive characterization, followed by antihepatic cancer evaluation using a diethyl nitrosamine-induced model (at a dose of 200 mg kg-1 BW). The study demonstrates a significant reduction in proinflammatory cytokines such as tumor necrosis factor-α, interleukin-6, interleukin-1β, and nuclear factor kappa beta (NF-κB). Furthermore, it confirms that the newly biosynthesized silver nanoparticles exhibit additional potential against hepatic cancer due to their capped biomolecules.

Biosynthesis and assessment of antibacterial and antioxidant activities of silver nanoparticles utilizing Cassia occidentalis L. seed

This research explores the eco-friendly synthesis of silver nanoparticles (AgNPs) using Cassia occidentalis L. seed extract. Various analytical techniques, including UV–visible spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive X-ray spectroscopy (EDX), were employed for comprehensive characterization. The UV–visible spectra revealed a distinct peak at 425 nm, while the seed extract exhibited peaks at 220 and 248 nm, indicating the presence of polyphenols and phytochemicals. High-resolution TEM unveiled spherical and oval-shaped AgNPs with diameters ranging from 6.44 to 28.50 nm. The SEM exhibiting a spherical shape and a polydisperse nature, thus providing insights into the morphology of the AgNPs. EDX analysis confirmed the presence of silver atoms at 10.01% in the sample. XRD results unequivocally confirm the crystalline nature of the AgNPs suspension, thereby providing valuable insights into their structural characteristics and purity. The antioxidant properties of AgNPs, C. occidentalis seed extract, and butylated hydroxytoluene (BHT) were assessed, revealing IC50 values of 345, 500, and 434 μg/mL, respectively. Antibacterial evaluation against Bacillus subtilis, Staphylococcus aureus, and Escherichia coli demonstrated heightened sensitivity of bacteria to AgNPs compared to AgNO3. Standard antibiotics, tetracycline, and ciprofloxacin, acting as positive controls, exhibited substantial antibacterial efficacy. The green-synthesized AgNPs displayed potent antibacterial activity, suggesting their potential as a viable alternative to conventional antibiotics for combating pathogenic bacterial infections. Furthermore, potential biomedical applications of AgNPs were thoroughly discussed.

Facile and Eco-Friendly Synthesis of Silver Nanoparticles using Semecarpus anacardium and their Antibacterial and Anticancer Activity

Plant extracts are utilized to synthesize nanoparticles containing bioactive compounds that can effectively decrease metal toxicity. In present study, the aqueous extracts of Semecarpus anacardium leaves and stems were used to reduce silver nitrate and synthesize silver nanoparticles (AgNPs), which have potent antibacterial and anticancer effects. The physico-chemical methods such as XRD, UV-Vis, Fourier transform IR and SEM were used to characterize the biogenci silver nanoparticles. These methods validated the synthesis of AgNPs with smaller size and homogeneously sphere-shaped AgNPs (10-50 nm) after incubation with S. anacardium leaf and stem extract. Stem extract derived AgNPs showed the significant cancer fighting abilities in the human breast (MDA-MB-231) and prostate adenocarcinoma (PC-3) cells compared to that of derived AgNPs. Stem extract derived AgNPs exhibits the significant antibacterial activity against E. coli and B. subtilis with respect to the gentamycin. Additionally, the study demonstrated that green synthetic AgNPs may be investigated for use as a treatment against bacterial infections.

Eco-Friendly Synthesis of Silver Nanoparticles Using Aqueous Extract of Ziziphus Spina-Christi Seeds: Characterization and Stability

In this study, silver nanoparticles (Ag-NPs) were prepared using an aqueous extract of Ziziphus Spina-Christi Seeds (ZSCS) powder as an eco-friendly material, reducing agent and capping ligand. The synthesized Ag-NP was characterized using UV-visible absorption spectroscopy (UV-Vis), Fourier transform infrared (FTIR), transmission electron microscopy (TEM) and dynamic light scattering (DLS). From The UV-Vis spectra, the surface plasmon resonance (SPR) absorption band at 443 nm confirmed the formation of Ag-NPs. The TEM results demonstrated that the synthesized Ag-NPs have mostly spherical shapes with a particle size of 21.54 nm. In addition, the particle size and the specific surface area (SSA) of Ag-NPs decreased with increasing ZSCS powder extract volume and AgNO3 concentration. The basic medium was found to be better than the acidic medium to prepare Ag-NPs. At a pH value equal to 9.5, within 30 minutes, the color of the solution was changed from colorless to brownish-orange. SPR absorption band of Ag-NPs demonstrated that the synthesized Ag-NPs have high stability over a period of 8 months. From FTIR results, the stretching of C-O group at 1223 and 1031 cm-1 disappeared after bioreduction of AgNO3, these results may be due to that Ag reduction was carried out by some hydroxyl groups that get oxidized at the expense of Ag+ because Ag+ is reduced to Ag-NPs.

Phytochemical, Total Phenolic, and Antioxidant Activity of Ginger Extract and Its Use in the Synthesis of Eco-friendly Silver Nanoparticles

The Ginger (Zingiber Officinale) extract contain a lot of constituents and elements. Ginger extract can effort as a good bio-reductant to produce silver nanoparticles (AgNPs). The AgNPs Green synthesis was achieved by using the Ginger plant extract with AgNO3. The green synthesis of AgNPs is the best developing procedure for preparation, since this process is easier than other procedures, eco-friendly and fewer times consuming. The produced AgNPs were characterizing via UV-Vis, FTIR, AFM, SEM, Zeta potential and EDX. The optimal conditions for the synthesis AgNPs which was confirmed through UV–Vis spectrophotometer. Also, the AgNPs has been characterized by AFM with average size of 53.45 nm, SEM with average size of 21.91 to 33.79 nm. Antioxidant and free radical scavenge activity are examined through TLC and DPPH test, the results shows that the Ginger have a high activity, moreover, this activity increased with characterized AgNPs.

Eco-friendly Synthesis of Silver Nanoparticles and its Application in Hydrogen Photogeneration and Nanoplasmonic Biosensing.

Environmentally friendly methods for silver nanoparticles (AgNPs) synthesis without the use of hazardous chemicals have recently drawn attention. In this work, AgNPs have been synthesized by microwave irradiation using only honey solutions or aqueous fresh pink radish extracts. The concentrations of honey, radish extract, AgNO3 and pH were varied. AgNPs presented mean sizes between 7.0 and 12.8 nm and were stable up to 120 days. The AgNPs were employed as co-catalyst (TiO2 @AgNPs) to increase the hydrogen photogeneration under UV-vis and only visible light irradiation, when compared to pristine TiO2 NPs. The prepared photocatalyst also showed hydrogen generation under visible light. Additionally, AgNPs were used to assemble a nanoplasmonic biosensor for the biodetection of extremely low concentrations of streptavidin, owing to its specific binding to biotin. It is shown here that green AgNPs are versatile nanomaterials, thus being potential candidates for hydrogen photogeneration and biosensing applications.

A rapid, high-yield and bioinspired synthesis of colloidal silver nanoparticles using Glycyrrhiza glabra root extract and assessment of antibacterial and phytostimulatory activity.

Silver nanoparticles (AgNPs) have emerged as highly effective antimicrobial agents against multidrug-resistant (MDR) pathogens. This study aims to employ green chemistry principles for AgNP synthesis involving phytochemical-rich extract from Glycyrrhiza glabra roots. The approach highlights using renewable feedstocks, safer chemicals, minimum byproducts, and process scale-up. The synthesis of AgNPs was assessed using a surface plasmon resonance band at 420 nm, and structural properties were characterized using TEM, x-ray diffraction, Fourier-transform infrared spectroscopy, and X-ray photoelectron spectroscopy. This method enables the production of high-yield dispersions of AgNPs with desired physicochemical characteristics, including dark yellow solution, size (~20 nm), spherical to an oval shape, crystal structure, and stable colloidal properties. The antimicrobial activity of AgNPs was investigated against the MDR bacteria strains of gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli). This work reveals that the antimicrobial activity of AgNPs can be influenced by bacterial cell wall components. The results demonstrate the strong interaction between AgNPs and E. coli, exhibiting a dose-dependent antibacterial response. The green approach facilitated the safer, facile, and rapid synthesis of colloidal dispersions of AgNPs, providing a sustainable and promising alternative to conventional chemical and physical methods. Furthermore, the effect of AgNPs on various growth parameters, including seed germination, root and shoot elongation, and dry weight biomass, was assessed for mung bean seedlings. The results revealed phytostimulatory effects, suggesting the promising prospects of AgNPs in the nano-priming of agronomic seeds. RESEARCH HIGHLIGHTS: Glycyrrhiza glabra root extract enabled rapid, high-yield, and eco-friendly synthesis of silver nanoparticles (AgNPs). Spectrophotometric analysis examined the optical properties, scalability, and stability of AgNPs. Transmission electron microscopy provided insights into the size, shape, and dispersity of AgNPs. Scanning electron microscopy revealed significant damage to gram-negative bacterial cell morphology and membrane integrity. AgNPs were found to enhance seed germination, seedling growth, and biomass yield of Vigna radiata.

Eco-Friendly Synthesis of Silver Nanoparticles by Nitrosalsola vermiculata to Promote Skin Wound Healing

Eco-friendly synthesis of silver nanoparticles (SN) by using a naturally occurring plant, such as Nitrosalsola (Salsola) vermiculata (SV), could be a novel way for appropriate wound healing. AgNO3 was reduced by SV to produce safe SN (SN-SV) extract and hasten the wound healing process. The obtained SN-SV were characterized by size, charge, wavelength, and surface morphology. The optimized formulation was dispersed in O/W cosmetic cream. Then, it was characterized in terms of pH, viscosity, homogeneity, and permeability. The ex vivo and in vivo studies have been conducted in a rat animal model to assess the potential of SN-SV cream on skin tissue regeneration. A skin punch biopsy was obtained to investigate the histopathological (HP) changes in the skin lesions of all rats by the H&E staining and PCNA immunostaining methods. The skin wounds in all subgroups were examined on days 5, 11, and 15 to analyze the effectiveness of SN-SV cream for treating surgical skin wounds. The prepared SN-SV had a particle size of 37.32 ± 1.686 nm, a charge of −1.4 ± 0.7 mV, non-aggregated SN-SV, and a λmax of 396.46 nm. The formed SN-SV cream showed a pH near the skin’s pH, with suitable viscosity and homogeneity and an apparent permeability of 0.009 ± 0.001. The HP changes in the SN-SV subgroups revealed a substantial reduction in wound size and improvement in wound granulation tissue formation and epidermal re-epithelialization (proliferation) compared to the healing in the SN subgroups. The current work revealed that SN-SV could be a novel skin-wound-healing agent with a practical application as a wound-healing platform.

The Effect of the Saudi Haloxylon ammodendron Shrub on Silver Nanoparticles: Optimal Biosynthesis, Characterization, Removability of Mercury Ions, Antimicrobial and Anticancer Activities

This research provides a sustainable way to treat water by removing heavy metal hazards (mercury ion) and biological pollutants (several strains of bacteria and fungi) through the eco-friendly synthesis of silver nanoparticles using the ethanol extract of the Saudi Haloxylon ammodendron shrub, which is planted in the Qassim desert. Further, this work confirms that these nanoparticles could be used as anticancer materials. The optimization factors of the biosynthesis of silver nanoparticles were studied and obtained (volume ratio = 1:2, pH = 7.5, and temperature = 60 °C). The scanning electron microscope micrographs showed the spherical shape and the huge numbers of silver nanoparticles accumulated, while X-ray diffraction measurements gave the crystal size of these nanoparticles in the range of 10.64 nm. The application findings of these biofabricated silver nanoparticles demonstrated effective detection and removal of different concentrations of mercury ions (0–2500 ppm) from the polluted aqueous solutions. The work revealed that Haloxylon ammodendron extract enhanced the antibacterial and antifungal activities of silver nanoparticles against different strains of bacteria and fungi. As well, the anticancer activity examinations of these nanoparticles and the extract showed good and reasonable results.

An Eco-Friendly Synthesis of Silver Nanoparticles Using Extract of Capsicum chinense Jacq. as A Bio-reducing Agent

Silver nanoparticles (AgNPs) have become popular due to their unique properties that can be used as biosensors, composite fibers, semiconductor materials, and other medical applications. Green synthesis of AgNPs using natural reagents from plant extract offers advantages as an efficient and environmentally friendly technique by which the compounds from the extract perform as bio-reductor for silver ions and the capping agent for stabilizing the AgNPs. Therefore, the purpose of the study was to conduct the synthesis of AgNPs by utilizing an extract of Capsicum chinensie Jacq as the bioreductor. The effect of extract concentrations, duration of exposure to sunlight, and temperatures on AgNPs formation was studied to obtain the optimum synthesis condition. The biosynthesized AgNPs characteristics were analyzed using UV-Vis Spectrophotometry, FTIR, SEM, X-Ray Diffraction, and PSA. The results showed that the higher extract concentration produced smaller AgNPs. The synthesis under sunlight exposure showed more product of AgNPs compared to heating on a hot plate. The optimum conditions of biosynthesis of AgNPs were attained at the volume ratio of extract (20%) and AgNO3 (1mM) of 1:1 and duration of sunlight exposure of 90 min, resulting in AgNPs characterized with maximum wavelength 422 nm and average particle sizes of 67.94 nm.

Green Synthesis: The Antibacterial and Photocatalytic Potential of Silver Nanoparticles Using Extract of Teucrium stocksianum.

Green synthesis is one of the promising pathways for biologically active nanoscale materials. Herein, an eco-friendly synthesis of silver nanoparticles (SNPs) was carried out using an extract of Teucrium stocksianum. The biological reduction and size of NPS were optimized by controlling the physicochemical parameters such as concentration, temperature, and pH. A comparison of fresh and air-dried plant extracts was also undertaken to establish a reproducible methodology. The biosynthesized SNPs were characterized by UV-Vis spectroscopy, FT-IR, SEM, DLS, and XRD analyses. The prepared SNPs exhibited significant biological potential against multi-drug-resistant pathogenic strains. The results revealed that the biosynthesized SNPs exhibit high antimicrobial activity at low concentrations compared to the parent plant extract. Minimum inhibition concentration (MIC) values were found between 5.3 µg/mL to 9.7 µg/mL for the biosynthesized SNPs, whereas the aqueous extract of the plant showed many high values of MIC, i.e., between 69 and 98 µg/ML. Furthermore, the synthesized SNPs were found efficient in the photolytic degradation of methylene blue under sunlight.

Pharmacological evaluation and kinetics of in vitro drug release efficacy of biofabricated silver nanoparticles using medicinally important Justicia neesii Ramamoorthy

Green nanotechnology, the science that utilizes various plant resources for the synthesis of nanoparticles without posing any chemical hazard has proved to be highly efficient and environment friendly technique. This opens up options for the synthesis of novel nanoparticles with desirable characteristics required for various application viz., biosensors, biomedicine, cosmetics, nanobiotechnology, as antimicrobials, electronics, sensing etc. In this context, here, we have made an attempt for cost effective and eco-friendly synthesis of silver nanoparticles (AgNPs) using the extract of medicinally important plant Justicia neesii Ramamoorthy. The phytochemical analysis of the extract exhibited the presence of glycosides, flavonoids, lignins, phenols, phytosterols, reducing sugars, saponins, etc. The absorbance peak of the biofabricated nanoparticles at 425 nm as indicated by UV-Vis spectrophotometer broadens with increase in time indicating their poly dispersity nature and particle size analyzer revealed the average size to be in the range of 20-45 nm. The antioxidant and antimicrobial activity of the synthesized AgNPs demonstrated promising results. The kinetics of in vitro drug release profile of the drug loaded AgNPs was carried out and the data obtained was correlated with various mathematical models. The drug release from AgNPs at both the pH’s shows good fit to the First order model which is obvious from the high values of coefficient of correlation which logically means that the release of drug from AgNPs is dependent on the concentration present within the nanoparticles.

Identifying the Anti-MERS-CoV and Anti-HcoV-229E Potential Drugs from the Ginkgo biloba Leaves Extract and Its Eco-Friendly Synthesis of Silver Nanoparticles.

The present study aimed to estimate the antiviral activities of Ginkgo biloba (GB) leaves extract and eco-friendly free silver nanoparticles (Ag NPs) against the MERS-CoV (Middle East respiratory syndrome-coronavirus) and HCoV-229E (human coronavirus 229E), as well as isolation and identification of phytochemicals from GB. Different solvents and high-performance liquid chromatography (HPLC) were used to extract and identify flavonoids and phenolic compounds from GB leaves. The green, silver nanoparticle synthesis was synthesized from GB leaves aqueous extract and investigated for their possible effects as anti-coronaviruses MERS-CoV and HCoV-229E using MTT assay protocol. To verify the synthesis of Ag NPs, several techniques were employed, including X-ray diffraction (XRD), scan, transmission electron microscopy, FT-IR, and UV-visible spectroscopy. The highest contents of flavonoids and phenolic compounds were recorded for acetone, methanol, and ethanol as mixtures with water, in addition to pure water. HPLC flavonoids were detected as apegenin, luteolin, myricetin, and catechin, while HPLC phenolic compounds were pyrogallol, caffeic acid, gallic acid, and ellagic acid. In addition, our results revealed that Ag NPs were produced through the shift from yellow to dark brown. TEM examination of Ag NPs revealed spherical nanoparticles with mean sizes ranging from 5.46 to 19.40 nm and an average particle diameter of 11.81 nm. A UV-visible spectrophotometric investigation revealed an absorption peak at λ max of 441.56 nm. MTT protocol signified the use of GB leaves extract as an anti-coronavirus to be best from Ag NPs because GB extract had moderate anti-MERS-CoV with SI = 8.94, while had promising anti-HCov-229E, with an SI of 21.71. On the other hand, Ag NPs had a mild anti-MERS-CoV with SI = 4.23, and a moderate anti-HCoV-229E, with an SI of 7.51.

Eco-friendly synthesis of silver nanoparticles using Eisenia bicyclis seaweed, their antimicrobial and anticancer activities.

Silver nanoparticle (AgNPs) production with antibacterial and antitumor properties is an important application in the medical field. This study introduces a novel organism that can be used for the large-scale production of AgNPs. The edible brown alga Eisenia bicyclis was used as a reducing agent to biosynthesize stable AgNPs. In this study, we achieved producing 50 mg AgNPs using only 1 g dried E. bicyclis seaweed. AgNP biosynthesis was performed at optimized conditions of a reaction temperature of 90°C, a seaweed extract concentration of 0.4%, and an AgNO3 concentration of 0.5 mM within 20 min, and the results showed that the formed nanoparticles are spherical and monodispersed with an average size 18.5±1.2 nm. The antibacterial activity of biosynthesized AgNPs was evaluated against some human clinical pathogens. Results showed that AgNPs had antibacterial activity against all tested bacterial strains, with the appearance of a clear zone equal to or larger than positive controls. Also, there was a concentration-dependent growth inhibition of in vitro cultured breast cancer cells treated with AgNPs and overexpression of p53 and Bax, and underexpression of Bcl-2. AgNPs synthesized by this method provide a potential source for antibacterial and anticancer applications.

Novel eco-friendly synthesis of silver nanoparticles using clove and cardamom extracts and cytotoxic and antimicrobial efficacies against oral pathogens- In vitro study

Background: Green synthesized nanoparticles are perceived as an inexpensive, safe & ecologically beneficent approach to control pathogenic oral microbes compared to conventional methods. In the current study, silver nano particles (AgNPs) were effectively synthesised using clove and cardamom plant extracts. Methods: In the present study, aqueous silver nitrate was reacted with the clove, cardamom extracts and characterization was analyzed using UV-vis spectrophotometer and TEM analysis. Clove and cardamom reinforced silver nanoparticles were examined at 25 µL, 50 µL and 100 µL concentrations for their antibacterial activity against Staphylococcus aureus, Streptococcus mutans, Lactobacillus species and Candida albicans. Cytotoxicity was assessed using brine shrimp assays. Results: The formation of AgNPs was observed as shifting in color from orange-red color to dark brown at the end of the day three. Reducing silver ions to AgNPs, as shown by UV-vis spectroscopy, has produced an emission peak at 462 nm. TEM imaging showed that the particles were spherical and varied in size from 5-20 nm. Antimicrobial activity of the AgNPs at 100 µL was superior to that of antibiotics against Streptococcus mutans. Excellent antibacterial activity was shown by a zone of inhibition that was closer to that of antibiotics when examined against Lactobacillus. Staphylococcus aureus and Candida albicans were also moderately impacted. There was no evidence of cytotoxicity. Conclusion: Silver nanoparticles reinforced with clove and cardamom exhibited no cytotoxicity and showed promise as a potent antibacterial agent against oral pathogensKey words: silver nanoparticles.

Green synthesis of silver nanoparticles from peel extract of Chrysophyllum albidum fruit and their antimicrobial synergistic potentials and biofilm inhibition properties.

Current methods for green synthesis of metal nanoparticles often require continuous harvesting of fresh bio-materials for every synthesis cycle. Practices and procedures that economize bio-materials need to be employed if green synthesis could become a sustainable and eco-friendly method for synthesizing metal nanoparticles. This study explores Chrysophyllum albidum peels (mostly regarded as waste) to prepare silver nanoparticles (Alb-AgNPs). The technique employed in the synthesis allows repeated use of the peels, thus, reducing the heavy dependence on bio-materials. The optical and structural properties of the Alb-AgNPs were studied with Scanning electron microscope, Fourier transform infrared spectrometer, UV-Vis spectrophotometer and powder X-ray diffractometer. The antimicrobial properties of the Alb-AgNPs were studied with selected microorganisms namely; S. aureus, E. coli, K. pneumoniae, B. subtilis, S. mutans, P. aeruginosa, S. typhi, and Candida albicans. High inhibitory activity against the microorganisms were exhibited with MICs ranging from 15.62 to 1000µg/mL. Again, the Alb-AgNPs showed the ability to enhance the efficacy of standard antimicrobial agents. The results of the combined interaction with standard antibacterial and antifungal agents ranged from synergistic to antagonistic effects against the tested microorganisms. In addition, the Alb-AgNPs could serve as a biofilm inhibitor with the highest percent inhibition of about 92% against methicillin-resistant Staphylococcus aureus. The results from this study thus provide access to the simple, sustainable, economic and eco-friendly synthesis of silver nanoparticles with efficient antimicrobial properties as drug candidates as a means of overcoming the prevailing antibiotic resistance menaces.

Sonochemical-assisted eco-friendly synthesis of silver nanoparticles (AgNPs) using avocado seed extract: Naked-eye selective colorimetric recognition of Hg2+ ions in aqueous medium

An easy and cost-effective protocol for colorimetric detection of potentially hazardous Hg2+ ions was developed through sonochemical-assisted eco-friendly synthesized silver nanoparticles (AgNPs). The AgNPs were prepared using the aqueous extract of avocado (AV) seed at room temperature. UV–visible spectroscopy revealed the formation of AV-AgNPs with a narrow surface plasmon resonance (SPR) band at 417 nm. FTIR analysis exposed the capping and stabilisation of phytoconstituents on the surface of AV-AgNPs. The average particle size was determined using a DLS profile to be 119 nm. FE-SEM images were revealed the spherical morphology of AV-AgNPs. In EDX spectra, AV-AgNPs exhibited a characteristic peak of Ag at ∼ 3 keV. Further, the unmodified AV-AgNPs were evaluated for colorimetric detection of different metal ions in aqueous medium. Surprisingly, these unmodified AV-AgNPs showed a good colorimetric selective sensing response towards Hg2+ ions. The colour of AV-AgNPs was changed from brown to colourless and accompanying the disappearance of the SPR band with blue shift. There was no distinct colour change and disappearance of SPR band for the other investigated metal ions. The detection limit of AV-AgNPs probe towards Hg2+ was 3.0 × 10−4 M. The redox reaction between AgNPs and Hg2+ ions could be the basis for a selective sensing mechanism. The AV-AgNPs probe showed a good linear response in the range of 25–200 μM towards Hg2+ with R2 value 0.9914. The exceptional performance of unmodified green synthesized AV-AgNPs suggested a very promising probe for on-site detection of Hg2+ in water sample.