Characterization Of Gold Nanoparticles Research Articles

Preparation and Characterization of Gold Nanoparticles from Bacterial Source and Their Separation Using Low-Cost Zirconia Composite Membrane

Preparation and Characterization of Gold Nanoparticles from Bacterial Source and Their Separation Using Low-Cost Zirconia Composite Membrane

Biosynthesis and Characterization of Gold Nanoparticles Using Microwave-Assisted Technology from Pomegranate (Punica granatum L.) Leaf Extract Produced by the Method of Supercritical Fluid Extraction (SFE)

Biosynthesis and Characterization of Gold Nanoparticles Using Microwave-Assisted Technology from Pomegranate (Punica granatum L.) Leaf Extract Produced by the Method of Supercritical Fluid Extraction (SFE)

Synthesized Gold Nanoparticles with Moringa Oleifera leaf Extract Induce Mitotic Arrest (G2/M phase) and Apoptosis in Dalton's Lymphoma Cells.

The therapeutic potential of chemically synthesized AuNPs has been demonstrated in various types of cancer. However, gold nanoparticles (AuNPs) synthesized using typical chemical methods have concerns regarding their environmental safety and adverse impact on human well-being. To overcome this issue, we used an environmentally friendly approach in which gold nanoparticles were synthesized using Moringa oleifera leaf extract (MLE). The present research was mainly focused on the biosynthesis and characterization of gold nanoparticles (AuNPs) using Moringa oleifera leaf extract (MLE-AuNPs) and explore its anticancer potential against Dalton's Lymphoma (DL) cells. Characterization of the MLE-AuNPs was conducted using UV-Vis Spectroscopy to confirm the reduction process, FTIR analysis to ascertain the presence of functional groups, and XRD analysis to confirm the crystallinity. SEM and TEM images were used to examine size and morphology. After characterization, MLE-AuNPs were evaluated for their cytotoxic effects on Dalton's lymphoma cells, and the results showed an IC50 value of 75 ± 2.31 µg/mL; however, there was no discernible cytotoxicity towards normal murine thymocytes. Furthermore, flow cytometric analysis revealed G2/M phase cell cycle arrest mediated by the downregulation of cyclin B1 and Cdc2 and upregulation of p21. Additionally, apoptosis induction was evidenced by Annexin V Staining, accompanied by modulation of apoptosis-related genes including decreased Bcl-2 expression and increased expression of Bax, Cyt-c, and Caspase-3 at both the mRNA and protein levels. Collectively, our findings underscore the promising anti-cancer properties of MLE-AuNPs, advocating their potential as a novel therapeutic avenue for Dalton's lymphoma.

Green synthesis and characterization of gold nanoparticles from discarded computer PCBs on reduction of environmental pollution

The economic value of gold content in electronic waste, particularly waste printed circuit boards (PCBs), has generated interest in recovering gold from this material. Unfortunately, due to the severe environmental hazards associated with such waste, there is a pressing need for efficient and selective methods of gold nanoparticle recovery. A novel technique has been developed to synthesize gold nanoparticles that employ chlorate leaching and Punica granatum extract to minimize the environmental impact of electronic waste. Multiple analytical methods, including UV-Vis, XRD, EDS, SEM, and TEM analysis, were utilized to identify and characterize the extracted gold nanoparticles. The UV-Vis spectrum showed GNP-absorption peaks at a narrow range of wavelengths, primarily at 520 nm, confirming the formation of gold nanoparticles from the e-waste. The XRD analysis identified the material as metallic gold with characteristic peaks of gold crystals (111), (200), (220), and (311), corresponding to the FCC crystal structure. The SEM and TEM analysis revealed that most of the Au nanoparticles were less than 40 nm in size, with some larger particles resulting from the agglomeration of smaller ones. The EDS spectrum analysis indicated that the gold atoms emitted strong signals. At the same time, other elements such as carbon, oxygen, and metals such as Sn, Zn, Pd, Cu, and Cd showed weaker signals. The recovered gold nanoparticles were found to have a bandgap of 2.2 eV, indicating that they are a direct bandgap semiconductor suitable for use in optoelectronic applications. The environmental impact of the PCBs and the chemicals used in the process were also analyzed to address the necessity of using discarded electronic waste to reduce environmental pollution. The proposed method showed high efficiency for extracting gold nanoparticles from e-waste, with simple process steps, low chemical usage, and low cost, as demonstrated by the results.

Evaluation of Lippia scaberrima Sond. and Aspalathus linearis (Burm.f.) R. Dahlgren extracts on human CYP enzymes and gold nanoparticle synthesis: implications for drug metabolism and cytotoxicity

BackgroundMetabolism is an important component of the kinetic characteristics of herbal constituents, and it often determines the internal dose and concentration of these effective constituents at the target site. The metabolic profile of plant extracts and pure compounds need to be determined for any possible herb-drug metabolic interactions that might occur.MethodsVarious concentrations of the essential oil of Lippia scaberrima, the ethanolic extract of Lippia scaberrima alone and their combinations with fermented and unfermented Aspalathus linearis extract were used to determine the inhibitory potential on placental, microsomal and recombinant human hepatic Cytochrome P450 enzymes. Furthermore, the study investigated the synthesis and characterization of gold nanoparticles from the ethanolic extract of Lippia scaberrima as a lead sample. Confirmation and characterization of the synthesized gold nanoparticles were conducted through various methods. Additionally, the cytotoxic properties of the ethanolic extract of Lippia scaberrima were compared with the gold nanoparticles synthesized from Lippia scaberrima using gum arabic as a capping agent.ResultsAll the samples showed varying levels of CYP inhibition. The most potent inhibition took place for CYP2C19 and CYP1B1 with 50% inhibitory concentration (IC50) values of less than 0.05 µg/L for the essential oil tested and IC50-values between 0.05 µg/L-1 µg/L for all the other combinations and extracts tested, respectively. For both CYP1A2 and CYP2D6 the IC50-values for the essential oil, the extracts and combinations were found in the range of 1 – 10 µg/L. The majority of the IC50 values found were higher than 10 µg/L and, therefore, were found to have no inhibition against the CYP enzymes tested.ConclusionTherefore, the essential oil of Lippia scaberrima, the ethanolic extract of Lippia scaberrima alone and their combinations with Aspalathus linearis do not possess any clinically significant CYP interaction potential and may be further investigated for their adjuvant potential for use in the tuberculosis treatment regimen. Furthermore, it was shown that the cytotoxic potential of the Lippia scaberrima gold nanoparticles was reduced by twofold when compared to the ethanolic extract of Lippia scaberrima.

Extraction of Synephrine from Waste Peels of Citrus sinensis and Green Synthesis of Gold Nanoparticles from it against Dermatophytes

The main object of the current work was to determine the antifungal efficiency of secondary metabolites product called synephrine that extracted from Citrus sinesis peels and the ability of synephrine to biosynthesis gold nanoparticles from HAucl4 which consider environmentally favourable method, then determine their activity against pathogenic human dermatophyte. The identification of synephrine done by Thin layer chromatography (TLC), High Performance Liquid Chromatography (HPLC) and The Fourier Transform Infrared (FTIR). The characterization of gold nanoparticles by using Ultra Violet-Visible Spectroscopy (UV-Vis), Field – Emission Scanning Electron Microscopy (FESEM) and Fourier Transform Infrared (FTIR), confirmed the biosynthesis of gold nanoparticles in diameter and morphology for AuNps biosynthesis by C. sinensis was 9.7-31 (nm) rounded to oval shape. The synephrine and AuNps that formed use it against some dermatophytes Trichophyton mentographytes, Trichophyton rubrum and Microsporum canis, the activity of synephrine against T. mentographytes at (10, 15 and 20 mg/mL) give less inhibition effect as compare with antifungal effect, while M. canis in 15 mg/mL show best effect than antifungal and for gold nanoparticles most concentration effective was (20 mg/mL).

Synthesis of AuNPs in microemulsion and nano-emulsion systems using aqueous extract of C. chayamansa leaves as reducing agent

This paper explores the synthesis and characterization of gold nanoparticles using various microemulsion and nano-emulsion systems. The pseudo-ternary system consists of an aqueous phase / Brij O10: 1,2-hexanediol (1:1) / castor oil; the aqueous phases include the aqueous extract of Chaya Maya (Cnidoscolus chayamansa) leaves or aqueous extract of Chaya maya leaves combined with the inorganic gold precursor. Chaya maya extract act as a reducing agent for gold (III) ions. The influence of aqueous phase content and surfactant concentration on gold nanoparticles size, morphology, and stability is investigated. Dynamic Light Scattering, Scanning Transmission Electron Microscopy, and UV-Vis spectroscopy are employed to analyze the synthesized gold nanoparticles. The sizes of the gold nanoparticles obtained were influenced by the system composition and are within the range of 19–40 nm. Results indicate that increasing the aqueous phase content generally leads to larger nanoparticle sizes, while higher surfactant concentrations yield smaller nanoparticles. A transition from microemulsion to nano-emulsion is observed at a specific aqueous phase content, marking a shift in nanoparticle size distribution and growth behavior. Additionally, microemulsion and nano-emulsion systems provide stability to gold nanoparticles, as evidenced by measured Zeta potentials indicating negatively charged surfaces conducting to colloidal stability. Also, remark that the use of organometallic precursors is no needed to obtain very good results on nanoparticle size and shape when O/W systems are used to this end. These findings highlight the potential of tailored microemulsion and nano-emulsion systems formulated with low-toxic components for controlling gold nanoparticles properties under mild conditions, contributing to the development of advanced gold nanoparticles-based materials with enhanced functionalities, with implications for diverse applications.

Biogenic Synthesis and Characterization of Gold Nanoparticles from Morus alba L. Leaves by Microwave Extraction Method

The aim of this study was to investigate the rapid, simple, and inexpensive biosynthesis and characterization of gold nanoparticles (AuNPs) an extract from leaves of Morus alba L. The generated gold nanoparticles were characterized by UV-Vis spectroscopy, TEM, FT-IR and zeta-sizer. For the biogenesis of gold nanoparticles, Morus alba L. (Mulberry) leaves and HAuCl4.3H2O solution were utilized as the starting ingredients. Fresh leaves of Morus alba L. were collected from Turkey (Trabzon). 100 mL of distilled water was mixed with 10 g of dried material for 120 minutes. The mixture was then extracted using a laboratory microwave for 4 minutes at 600 W. For the biosynthesis of AuNPs, different amounts 100 ml of (0.5 mM, 1 mM) aqueous HAuCl4.3H2O solution of leaf extract (0.5 and 1 mL) were mixed with HAuCl4. 3H2O solution, and then the mixture was placed in a household microwave at 90 W for 1 to 30 minutes. UV-vis spectroscopy, TEM, FT-IR and zeta-sizer were performed to characterize the produced gold nanoparticles. UV-Vis absorption spectra was measured using a Shimadzu UV-1240 UV-Vis spectrophotometer with a wave length range of 300 to 800 nm. The development of AuNPs was indicated by the mixture's purple-red colour. From the results of zetasizer study, the average particle size of the AuNPs was 78.95±0.57 nm, the zeta potential was 12.9±0.808 mV, and the polydispersity index was 0.321±0.004. When the AuNP solutions were kept in the refrigerator, their UV-Vis absorption spectra rarely changed and remained stable for around 2 to 2.5 months.

Green synthesis, characterization of gold nanoparticles using Gundelia tournefortii leaf extract, and its cytotoxic activities

The present study focused on the environmentally friendly preparation, characterization, and certain biological activities of gold nanoparticles (Au-NPs) made with the Gundelia tournefortii (kenger) leaf extract. The results from devices such as transmission electron microscope, energy-dispersive x-ray spectrophotometer, and Fourier scanning electron microscope reveal the structures of nanoparticles. After an hour, the greatest surface plasmon resonance was discovered at 532.15 nm. The mean cubic crystallite size was calculated using the powder x-ray diffraction model and was found to be 23.53 nm. It was noted that the produced Au-NPs had spherical forms and hexagonal dimensions and ranged in size from 5 to 40 nm. The minimum inhibitory concentration and a colorimetric method for determining cell metabolic activity test, respectively, were used to investigate the suppressive effects of Au-NPs on the growth of pathogenic bacteria and healthy and cancer cell lines.

Determination and Characterization of Gold Nanoparticles in Liquor Using Asymmetric Flow Field-Flow Fractionation Hyphenated with Inductively Coupled Plasma Mass Spectrometry.

The EU has approved the usage of gold as a food additive (E175) and it has been applied in numerous foods for coloring and decoration purposes. Different from the general assumption that edible gold is mainly present in the form of flakes or external coating in foods, this work demonstrated that gold nanoparticles (Au NPs) can be released from gold flakes and extracted under optimized conditions. To support future risk assessment associated with the exposure of Au NPs to human health, an effective approach was established in this study for both size characterization and mass determination of Au NPs released in a commercial gold-containing liquor using Asymmetric Flow Field-flow Fractionation (AF4) hyphenated with Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Our results showed that no Au NPs were detected in the original liquor product and only after ultrasonication for several minutes did Au NPs occur in the ultrasound-treated liquor. Particularly, Au NPs released in the liquor can be well extracted after 100-fold enrichment of gold flakes and the subsequent ultrasonication for 25 min. Size characterization of Au NPs was conducted by AF4-ICP-MS under calibration with Au NP standards. The gold particle sizes detected ranged from 8.3-398.0 nm and the dominant size of the released Au NPs was around 123.7 nm in the processed liquor. The mass concentration of gold particles determined in the liquor sample with gold flakes concentrated and subsequently sonicated was 48.1 μg L-1 by pre-channel calibration and the overall detection recoveries ranged over 82-95%. For the comparison control samples without ultrasonication, there was no detection of Au NPs. The established method was demonstrated to be useful for monitoring Au NPs in liquor and is possibly applied to other similar foodstuffs.

Synthesis and characterization of gold nano particles using barleria cristata for antimicrobial and anticancer applications

A nano revolution is necessary for the integration of nanoscience and medicine. Drug delivery, electronics, biological sciences, optics, and catalysis are among the fields in which metal nanoparticles find application. The objective of this work is to extract leaves from Barleria cristata in order to produce ecologically friendly gold nanoparticles (Au NP) for pharmacological studies. Several human pathogens were used to assess the biological mechanism and antibacterial properties of gold nanoparticles (AuNPs) in relation to their potential as a cancer treatment. An aqueous extract with a natural pH of 7.4 was obtained by reacting with 1 mM chloroauric acid (HAuCl4.3H2O), and it was then kept at room temperature. The colour changed from pale yellow to pink right away, indicating the reduction of Au3+ ions to Au 0. Using a UV-Visible spectrophotometer, the synthesised AuNPs were seen. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), field emission transmission electron microscopy (FE-TEM), and particle size distribution and zeta potential analysis are a few examples of analytical techniques. The disc diffusion method was used to confirm the extract's antibacterial properties in vitro on a few human illnesses. The MTT test was used to confirm the extract's anticancer properties on Hela carcinoma cell lines, revealing IC50 values of 50 μg/mL.

Fabrication and characterization of gold nanoparticles using alginate: In vitro and in vivo assessment of its administration effects with swimming exercise on diabetic rats.

Gold nanoparticles (AuNPs) have unique features that might lead to the development of a new class of diabetic medicines. AuNPs were biosynthesized utilizing sodium-alginate. UV-Vis-spectroscopy, Fourier transforms infrared, field emission scanning electron microscopy (FESEM), and energy dispersive X-ray were used to examine the particles. The potential of AuNPs for improving the diabetes condition was examined along with swimming in rats. FESEM image revealed the spherical morphology with an average particle size of 106.6 ± 20.8 nm. In the diabetic group, serum glucose, blood urea nitrogen (BUN), creatinine, cholesterol, and triglyceride (TG) levels were significantly higher than the control group. Low-density lipoprotein (LDL) was significantly higher and high-density lipoprotein (HDL) was significantly lower in the diabetic group compared to the control group. Malondialdehyde (MDA) levels were also significantly higher in the D group. However, in the groups treated with swimming and gold, these parameters were significantly improved. Specifically, serum-glucose, BUN, creatinine, cholesterol, and TG levels were significantly reduced, while LDL was significantly decreased in the diabetic + swimming + AuNPs group and HDL was significantly increased in the diabetic + AuNPs group. MDA levels were significantly decreased in the treated groups, and other antioxidants were significantly improved in the diabetic + swimming + AuNPs group. Catalase levels were also significantly improved in the D + gold group. It can be concluded that both AuNPs and swimming can decrease diabetic complications.

Biosynthesis and Characterizations of Gold Nanoparticles (AuNPs) Prepare Using Different Age Classes of <i>Marphysa moribidii </i>(Polychaetes) Extract as Biogenic Reducing Agents

The utilization of Marphysa moribidii, a local marine baitworm (Polychaeta), as a possible biogenic reducing agent in the synthesis of AuNPs was successfully performed. In this particular study, different age classes of M. moribidii based on their body widths that classified as Class I (3 – 5 mm), Class II (6 – 8 mm), and Class III (9 – 11 mm) were employed in the biosynthesis of AuNPs. The use of different age classes of M. moribidii for the biosynthesis of AuNPs is a fascinating approach that takes advantage of the varying metabolic activities of the different age groups. The colour changes of the solution from yellow to red ruby is the initial observation for the successful biosynthesis of AuNPs where AuNPs_II shows the fastest changes of colour after 2 h incubation and maintains stable for over 1 month of storage. Further confirmation was depicted from the existence of surface Plasmon resonance (SPR) absorption peaks in a range of 545 – 552 nm from UV-Vis spectroscopy. TEM analysis shows the formation of spherical-like shape of biosynthesis AuNPs with average particle size around 42 – 57 nm where AuNPs_II had the smaller particle size. Lastly, the antibacterial assessment of biosynthesized produced from different age classes of M. moribidii had good antibacterial activity against Gram-negative bacteria, but poor activity against Gram-positive bacteria. AuNPs produced from Class II M. moribidii (AuNPs_II) provide the highest ZOI value of 13 mm. The utilization of different age classes of M. moribidii for the biosynthesis of metal nanoparticles is an interesting pathway for designing a novel method that can be considered nature-friendly, safe, and hopeful for the future.

Synthesis and characterization of gold nanoparticles using Brevibacterium casei (SOSIST-06) isolated from Southern Ocean water samples and their in vitro and in silico anti-WSSV activity

The worldwide shrimp aquaculture business, which is expanding and producing food, has experienced significant economic losses due to a variety of disease outbreaks. One of the main viral pathogens for the global shrimp aquaculture sector is the white spot syndrome virus (WSSV). There have been several attempts to eradicate the virus in shrimp, but none of them have been successful in the long-term effectiveness. In the present work, we establish the isolated strain identified as Brevibacterium casei SOSIST-06 from the Southern Ocean water sample and its capacity for green synthesis of gold nanoparticles. The nanoparticles were characterized using UV–vis spectroscopy, X-ray diffraction, and Transmission electron microscopy. The morphology of nanoparticles is most spherical and there are a few triangles with an average size ranging from 9.5 to 52.3 nm. In vitro anti-wssv activity was carried out using hybrid cell line PmLyo-Sf9 cells, and the synthesized gold nanoparticles were shown to inhibit the virus infection (attachment inhibitory and virucidal activity) with a dose-dependent effect. Further, the interaction of gold nanoparticles and VP28 envelope protein was confirmed using in silico approach. To our knowledge, this is the first study to identify that an actinobacterium, Brevibacterium casei synthesized gold nanoparticles could fight against the white spot syndrome virus. These findings do point the way towards creating potent antiviral or therapeutic techniques for aquaculture that utilize gold nanoparticles.

GC–MS metabolomics profile of methanol extract of Acacia modesta gum and gum-assisted fabrication and characterization of gold nanoparticles through green synthesis approach

Hereunder, for the first time, we reported phytocompounds in the methanolic extract of Acacia modesta (AM) gum through Gas chromatography-mass spectrometry (GS-MS). Further, the AM gum aqueous solution was used for gold nanoparticles (AuNPs) synthesis through a simple, swift, eco-friendly, and less costly green synthesis approach. A total of 108 phytocompounds (63 with nonpolar, 45 with polar column) were identified in the gum extract, which includes fatty acids, alcohols, sterols, aldehyde/ketones, furans, aromatic compounds, esters, phenols, terpenes, sugar derivatives, alkaloids, and flavones. From three used concentrations (5, 10, and 15 mg/mL) of the AM gum aqueous solution, the 15 mg/mL gum solution resulted in more successful AuNP synthesis with a smaller size, which was visualized by a rusty red color appearance. UV–Visible absorption spectroscopy revealed the characteristic surface plasmon resonance (SPR) of AuNPs in aqueous solution at 540 nm. Dynamic light scattering (DLS) measurement of NPs solution revealed a hydrodynamic diameter of 162 ± 02 nm with the highest gum concentration where core AuNPs diameter was 22 ± 03 nm, recorded by Transmission electron microscopy. Zeta potential revealed fair stability of AuNPs that was not decreased with time. Catalytic activity experiments revealed that AM gum-based AuNPs can increase the rate of the reduction of methylene blue 10 times in comparison with AM gum extract alone. Results from this study showed that a diverse array of phytocompounds in AM gum can successfully reduce gold ions into gold nanoparticles, which can be used further in different pharmaceutical and industrial applications.

Microwave assisted production and characterization of gold nanoparticles using green tea and catechin extracts obtained by supercritical extraction method

Microwave assisted production and characterization of gold nanoparticles using green tea and catechin extracts obtained by supercritical extraction method

Green synthesis, characterization, and biological evaluation of gold and silver nanoparticles using Mentha spicata essential oil

Green synthesis of bioactive nanoparticles (NPs) is getting more attractive in various fields of science including the food industry. This study investigates the green synthesizing and characterization of gold NPs (AuNPs) and silver NPs (AgNPs) produced using Mentha spicata L. (M. spicata) essential oil as well as their antibacterial, antioxidant, and in vitro cytotoxic effects. The essential oil was mixed with both Chloroauric acid (HAuCl4) and aqueous silver nitrate (AgNO3) solutions separately and incubated at room temperature for 24 h. The chemical composition of the essential oil was identified by gas chromatography coupled with a mass spectrometer detector (GC–MS). Au and Ag nanoparticles were characterized using UV–Vis spectroscopy, transmission electron microscopy, scanning electron microscopy, dynamic light scattering (DLS), X-ray diffraction (XRD) and Fourier transform infrared (FTIR). The cytotoxicity of both types of nanoparticles was evaluated using MTT assay on cancerous HEPG-2cell line by exposing them to various concentrations of both NPs for 24 h. The antimicrobial effect was evaluated by the well-diffusion technique. The antioxidant effect was determined by DPPH and ABTS tests. According to the results of GC–MS analysis, 18 components were identified, including carvone (78.76%) and limonene (11.50%). UV–visible spectroscopy showed a strong absorption peak of 563 nm and 485 nm, indicating the formation of Au NPs and Ag NPs, respectively. TEM and DLS demonstrated that AuNPs and AgNPs were predominantly spherical shaped with average sizes of 19.61 nm and 24 nm, respectively. FTIR analysis showed that biologically active compounds such as monoterpenes could assist in the formation and stabilization of both types of NPs. Additionally, XRD provided more accurate results, revealing a nano-metal structure. Silver nanoparticles exhibited better antimicrobial activity against the bacteria than AuNPs. Zones of inhibition ranging 9.0–16.0 mm were recorded for the AgNPs, while zones of 8.0–10.33 mm were observed AuNPs. In the ABTS assay, the AuNPs and AgNPs showed a dose-dependent activity and synthesized nanoparticles exhibited higher antioxidant activity than MSEO in both assays. Mentha spicata essential oil can be successfully used for the green production of Au NPs and Ag NPs. Both green synthesized NPs show antibacterial, antioxidant, and in vitro cytotoxic activity.

Synthesis and characterisation of gold nanoparticles from acacia leaf and to evaluate anticariogenic activity.

To synthesise the gold nanoparticles (AuNPs) using Acacia catechu through biogenic synthesis and evaluate their antimicrobial efficacy against S. mutans and E. coli in vitro. Green synthesised AuNPs were characterised using the ultraviolet-visible (UV-Vis) spectroscopy, and the size and shape of the synthesised nanoparticles were evaluated using the transmission electron microscopy (TEM). The antimicrobial efficacy of AuNPs (30/60/100 μl) against S. mutans/E. coli was evaluated on the Mueller-Hinton agar by measuring the zone of inhibition (ZOI) with ampicillin (15 μl) as a positive control. The synthesised AuNPs were confirmed using the UV-Vis spectroscopy with peaks at 540 nm, and the size of the particle estimated using the TEM was between 5 and 15 nm. The antimicrobial efficacy of AuNPs was comparable to that of ampicillin against S. mutans/E. coli, but the difference was not significant. The antimicrobial effects increased in a dose-dependent fashion but were comparable across all concentrations and ampicillin. Green synthesised AuNPs exhibited significant antibacterial activity against S. mutans and E. coli at par with commercial ampicillin and demonstrated the potential towards anticariogenic agent for future use in dentistry.

Studying the effect of Gold Nanoparticles on some bacterial species isolated from surgical wound infections

The process of synthesis of gold nanoparticles biologically is a safe, environmentally friendly and inexpensive method and had an effect on the most common bacterial species in surgical inflammation, as the gold particles were synthesized in a biological way and no toxic substance was used, as secondary metabolites (K. pneumoniae) as a reducing agent of HAuCL4.4H2O chloric acid to gold nanoparticles. Characterization of gold nanoparticles was carried out using ultraviolet spectroscopy, which showed that the absorption peak was at 572 nm. The infrared absorption spectrum showed several peaks ranging between (600-4000) evidence of the interference of gold nanoparticles with the particles contained in the bacterial suspension (leachate), and transmission electron microscopy (TEM) images showed that gold nanoparticles were spherical in shape, and X-ray diffraction examination showed that they are particles of spherical shape. Nano-gold compared to the reference card (ICDD card No.03-065-2870).

Green synthesis and characterization of gold nanoparticles using anthocyanins from Rubus palmeri

BACKGROUND: The green synthesis of nanoparticles based on noble metals has been researched in the last decades. The physical and optical properties of gold, along with the metabolites found in plant extracts that work as capping agents, allow the development of materials that can be used in alternative therapies in human health. OBJECTIVE: This study reports the obtention of gold nanoparticles (AuNPs) through a green synthesis process, using purified anthocyanins (ACNs) from Rubus palmeri berries as reducing and stabilizing agents. RESULTS: The colloidal solution obtained with a ratio of 1.6 mg: 0.6 mM (ACNs:HAuCl4) was monitored through UV-Vis spectroscopy over 10 h at 30°C, producing a surface plasmon resonance (SPR) signal at 540 nm. The interaction between the ACNs and the AuNPs was analyzed through Fourier-transform infrared spectroscopy (FTIR). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) determined an average size of 13 nm with a spherical morphology predominance at 30°C, while at 20°C triangular morphologies appeared. Energy-dispersive X-ray spectroscopy (EDX) and elemental mapping showed predominance of the gold element. The antioxidant activity was analyzed by ORAC and ABTS assays, showing a variation of up to four times the EC50 between the AuNPs and the ACNs. CONCLUSION: These results determined the role of ACNs in the green synthesis of AuNPs and their capability to induce various morphologies at different temperatures.