Biological Synthesis Of Gold Nanoparticles Research Articles

Biogenic Synthesis of Gold Nanoparticles using Bark Extract of Bauhinia variegata: Antibacterial and in vitro Anticancer study

Our study revealed the biological synthesis of gold nanoparticles (AuNPs) using aqueous bark extract of plant named Bauhinia variegata (Kaanchnar). Biomolecules present in the plants act as a reducing and capping agent. In this reduction reaction, gold (III) metal was reduced by biomolecules present in plants leading to formation of AuNPs. Biosynthesized AuNPs were characterized by spectral analysis (XRD, FTIR, UV-visible) and imaging microscopy. Antibacterial study of the biosynthesized AuNPs was examined against Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) bacteria using agar well diffusion method and AuNPs exhibited an excellent inhibition zone against mentioned bacteria. In vitro anticancer study of AuNPs was performed on MCF-7 cell line. Compared to standard drug, AuNPs exhibited potent anticancer activity with the IC50 value 15.55 μg/ml.

Anti-cancer activity of Hypnea valentiae seaweed loaded gold nanoparticles through EMT signaling pathway in A549 cells

The biological synthesis of gold nanoparticles (AuNPs) offers enormous promise for the formulation of a new generation anti-carcinogenic drugs. In this study, AuNPs were eco-friendly synthesized using the marine red algae species, Hypnea valentiae. Multiple spectroscopic methods were used to confirm and characterized the synthesized Hv-AuNPs. UV spectroscopy revealed 540 nm is where Hv-AuNPs' Surface Plasmon Resonance (SPR) peak. Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) showed that Hv-AuNPs were 7–45 nm size ranges with round shapes. With the help of an X-ray Diffraction (XRD) spectrum, the crystalline nature of Hv-AuNPs was found, and FTIR analytical tools were used to find the organic compounds, like phenols and carbonyl molecules, that were involved in the reduction of Hv-AuNPs. The biosynthesized Hv-AuNPs' potential to scavenge free radicals was measured using the DPPH test (84.5 ± 1.45%), the hydrogen peroxide assay (70.6 ± 0.8%) and the FRAP assay (90.54 ± 2.3%). Lung cancer (A549) cells were used to test the anti-cancer effects of Hv-AuNPs through EMT signaling pathway (E-cadherin, Vimentin and SNAIL). The Hv-AuNPs showed strong cytotoxic activity against lung cancer cells (IC50 = 23.68 μg/mL) and the nanoparticles effectively control the cell migration and colony formation at 50 μg/mL. The RT-PCR gene expression analysis confirmed the Hv-AuNPs potentially downregulated the Vimentin expression at 50 μg/mL and demonstrated high anti-cancer activity. Therefore, this investigation found that H. valentiae synthesized AuNPs have high therapeutic potential for lung cancer and suggests their use in drug development.

Green synthesis of gold nanoparticles via Capsicum annum fruit extract: Characterization, antiangiogenic, antioxidant and anti-inflammatory activities

Biological synthesis of gold nanoparticles (AuNPs) is gaining attention of researchers because of their varieties of biomedical applications. This study reported the novel, eco-friendly synthesis of AuNPs using dried fruit extract of Capsicum annum (C. annum). Biosynthesized gold nanoparticles (Ca-AuNPs) showed UV absorption peak at 540 nm and were found to be stable for up to three months. The nanoparticles were further characterized by Transmission Electron Microscopy (TEM), Fourier Transform Infrared (FT-IR), Energy Dispersive X-ray Analysis (EDAX) and X-ray diffraction (XRD) analysis. The nanoparticles were spherical in shape with size range of 20–30 nm and zeta potential study confirmed the surface charge of -26.5 mV. The Ca-AuNPs were tested for anti-angiogenic activity using Chorioallantoic membrane (CAM) assay that implied a significant anti-angiogenic efficiency of Ca-AuNPs at 100 µg/mL concentration. The antioxidant activity of Ca-AuNPs studied by 2,2- diphenyl-1-picrylhydrazyl (DPPH) assay was found to be significant with 86.0% radical scavenging activity. These nanoparticles also revealed anti-inflammatory activity at concentration range 100–1200 µg/mL with IC-50 value619.4 µg/mL. The present study includes synthesis of Ca-AuNPs by using phytoconstituents of plant material as reducing agents to efficiently exploit the biomedical applications of the nanoparticles.

Biosynthesis, Characterization, Anticancer activity and Drug delivery of Gold Nanoparticles synthesised from local isolate of Proteus mirabilis

Intracellular metal nanoparticles are produced by a variety of bacteria. As aqueous gold reacts with the Proteus mirabilis, it grows resulting in the formation of gold nanoparticles. The use of microorganisms in nanoparticle synthesis is gaining traction as an environmentally sustainable and exciting gold recovery process. This study consist of biological synthesis of gold nanoparticles utilizing the culture supernatant of local bacteria. Proteus mirabilis isolates when treated with HAuCl₄ solution in 10⁻³ Mm, then AuNPs were characterized and examined for anticancer ability using MTT assay against MCF-7 breast cancer cell lines. The size of the gold nanoparticles was rather consistent 29.18-55.57nm. Anticancer behavior studies revealed that gold nanoparticles had an equivalent strong anticancer impact. On the MCF-7 cell line, the AuNP concentration of 400 g/ml showed the greatest decrease. In addition, the combination of 400 g/ml AuNPs + 20 μM cisplatin resulted in the greatest reduction in the MCF-7 cell line.

Green tea extract mediated biogenic synthesis of gold nanoparticles with potent anti-proliferative effect against PC-3 human prostate cancer cells

This study examines the biological synthesis of gold nanoparticles using Camellia sinensis L. (green tea) and their cytotoxicity against human PC-3 prostate cancer cells. The green tea extract-mediated biogenic synthesis of gold nanoparticles (GT-AuNPs) via green tea extract synthesis was validated using UV–vis spectroscopy, SEM, EDS, TEM, DLS, and XRD techniques. Additionally, the tetrazolium assay was utilized to investigate the anti-proliferative effect of GT-AuNPs generated by biosynthesis. The findings suggest that the biosynthesized GT-AuNPs reduced PC-3 cell proliferation with an IC50 of 19.71 g/mL during 24 h. These findings imply that GT-AuNPs exert their anti-proliferative action on the PC-3 cell line by inhibiting growth, decreasing DNA synthesis, and triggering apoptosis. After treatment, morphological examination of PC-3 cells exhibited surface detachment, cell shrinkage, and cell body distortion, indicating that GT-AuNPs had a cytotoxic effect on PC-3 cells.

Biological Synthesis of Gold Nanoparticles from Suspensions of Green Microalga Dunaliella salina and Their Antibacterial Potential

Biological Synthesis of Gold Nanoparticles from Suspensions of Green Microalga Dunaliella salina and Their Antibacterial Potential

Experimental Investigations on Behaviour of Rhamnolipid Biosurfactant as a Green Stabilizer for the Biological Synthesis of Gold Nanoparticles

Use of biosurfactant as a stabilizer for the biological synthesis of gold nanoparticles (AuNPs) is now emerging as a nontoxic and environmentally acceptable green chemistry procedure. Stability of AuNPs at different pHs is very important because our body has different pHs. This paper addresses this issue. In this work, first P. aeruginosa PTCC 13401 was used to produce rhamnolipid biosurfactant. The highest rhamnolipid production occurred at 120 h, achieving a value of 3.1 g/L. The thin layer chromatography (TLC) indicated that the crude product is a mixture of mono-rhamnolipid and di-rhamnolipid with retardation factor (Rf) value of about 0.35 and 0.78, respectively. Moreover, rhamnolipid solutions with different pHs were added to HAuCl4 solution and incubated for 24 h at 37 oC and 150 rpm. The formation of spherical AuNPs was monitored using a UV–vis spectrophotometer and verified by TEM. Our results showed that the formation of AuNPs occurred just for pH values between 7.0 -8.0. Measurement of the surface tension of the solution at different pH values was performed to find out the reason for this observation. Our results showed that the surface tension was also stable only between pH 7.0-8.0. This was inferred from precipitation of rhamnolipid at higher and lower pH values. The results of this work may help pharmacists to have a good prediction of behavior of rhamnolipid biosurfactants as a stabilizer for biomedical applications including tissue engineering and drug delivery.

Ethnobotanical biosynthesis of gold nanoparticles and its downregulation of Quorum Sensing-linked AhyR gene in Aeromonas hydrophila

This study highlights and combines the advantages of quorum sensing inhibition using scientifically untapped medicinal plants, the ethnobotanicals, through an effective drug delivery system, nanotechnology, to develop antivirulence drugs to control aquaculture pathogens. The ethnobotanical extracts and biologically synthesized gold nanoparticles of the Ilongot-Eǵongot community show antibacterial activity against gram-negative Aeromonas hydrophila. The ethnobotanical crude extracts (CEs) and crude extracts + gold nanoparticles (CEs + AuNPs) exhibit Quorum Sensing Inhibition activity through inhibition of the biofilm formation in A. hydrophila. Moreover, ethnobotanical CEs + AuNPs show much greater activity than its counterpart CEs in antibacterial and biofilm formation assay in A. hydrophila. Thus, this study supports the use of biological synthesis of gold nanoparticles to improved drug delivery which indicate the potential of these ethnobotanicals for therapeutic approach in inhibiting bacterial virulence without developing resistance.

Biosynthesis of Gold Nanoparticle using Cell-free Extract of Clinical Isolates Staphylococcus Aureus and Escherichia Coli

Present study reports on biological synthesis of gold nanoparticles using cell free extract of Staphylococcus aureus and Escherichia coli. The cold extract is allowed to react with both 1mM and 10 mM solutions of HAuCl4 which showed a colour change from yellow to dark cherry red after 1 hr. Gold nanoparticle formation is confirmed with UV-Visible spectrophotometer at 547nm.The 10mM concentration is found to be better for synthesis of more NPs using E. coli. XRD pattern exhibited 2θ values38.18o, 44.39o, 64.58o, 77.55o of 2θ value, corresponding to Bragg’s diffraction at 111, 200, 220 and 311 plane of lattice structure closely matching with the standard values given in ICDD reference file. SEM analysis revealed morphological characteristics of nanoparticles of different sizes ranging from 70 to 200 nm. Thus, the present study throws new light on the suitability of E. coli as an alternative for conventional methods of chemical synthesis of gold nanoparticles.

Biosynthesis and Chaerchterization of Gold Nanoparticals by Using Local Serratia spp. Isolate

Biological sources of bacteria ,fungi, and plants are playing a major role in the reduction of metallic nanoparticles such as gold, as it attributed as an eco-friendly and contributed in application in nanotechnology. This study include the biological synthesis of gold nanoparticles using the culture supernatant of local Serratia spp. isolate. Gold(III) chloride trihydrate ( HAuCl2) in concentration1× 10-³ M added to supernatant separately. Their respective supernatants were examined for ability to produce gold nanoparticles, The events happend was in a dark place at 37Cº. After 24 h, it was observed that the color of the solutions turned from pale yellow to dark purple. The gold nanoparticles were characterized by: UV-Visible spectroscopy, Fourier transform infrared spectroscopy (FTIR) to ensure presence of different functional groups, respectively ,X-Ray Diffraction Analysis (XRD), finaly,scanning electron microscopy (FE-SEM) to determined AuNPs size and shape. Results: The gold nanoparticles were approximatly uniform in size 57.17 nm , triangle in shape and FTIR spectra revealed the presence of various functional groups in the gold nanoparticles which were also present in the bacterial extract. Conclusion: The current approach suggests that rapid synthesis of nanoparticles would be feasible in developing a biological process for mass scale production of gold nanoparticles.

A review of the biological synthesis of gold nanoparticles using fruit extracts: scientific potential and application

Gold nanoparticles (GNPs) are well-known nanomaterials that can be used for multiple biomedical applications. There are various methods for synthesis of GNPs using microorganisms and plants, particularly through the use of fruit extracts. Their use is due to the fact that fruit extracts are the natural concentrate of substances that possesses therapeutic properties. In this review, we aim to compare the recent studies concerning the methods for synthesis of GNPs from fruit extracts, the methods used to characterize the properties of GNPs and capping biomaterial and the potential applications of GNPs. The most frequently used methods to characterize GNPs and capping biomaterial are UV–visible spectroscopy, transmission or scanning electron microscopy, dynamic light scattering and Fourier transformation infrared spectroscopy techniques. Because of GNPs’ optoelectronic properties, biocompatibility, stability and oxidation resistance, they can be used in areas such as electronics, chemical and biological sensing, tumour imaging, drug delivery and phototherapy.

Biological synthesis of gold nanoparticles by the diatom Stephanopyxis turris and in vivo SERS analyses

Cultivation of the sea water diatom Stephanopyxis turris (S. turris) in a gold salt containing medium leads to the formation of gold nanoparticles. These biosynthesized nanoparticles were characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), and selected area electron diffraction (SAED). According to their diameter, they are classified into two groups with average diameters of around 30 and 10nm. It is demonstrated that both types of nanoparticles consist exclusively of gold. The location of the gold nanoparticles with respect to the diatom cell was revealed using surface enhanced Raman scattering (SERS). To ensure a reliable observation of SERS spectra in each measured cell, the concentration of the gold solution as well as the incubation time of S. turris in this solution were optimized. 3D Raman imaging of entire S. turris cells was performed to localize SERS spectra of compounds resulting from closely neighbored nanoparticles. Interestingly, intracellular SERS spectra were observed indicating the presence of gold nanoparticles inside S. turris cells. Further investigation shows that the SERS spectra generated by biosynthesized nanoparticles differ significantly from the conventional Raman spectrum of diatoms. While pigments are dominating the resonance enhanced Raman spectrum, SERS spectra exhibit a completely different appearance. Their bands coincide with bands in SERS spectra of various biologically relevant compounds, e.g., hydroxyurea and retinol. The biosynthesized gold nanoparticles therefore have a high potential for prospective in vivo research of algal metabolism and its regulation.

Eco-Friendly and Temperature Dependent Biosynthesis of Gold Nanoparticles Using the Bacterium <i>Pseudomonas aeruginosa</i>: Characterization and Antibacterial Activity

Abstract. In this paper we report the biological synthesis of gold nanoparticles (GNPs) by the reduction of gold ions using a suspension and supernatant of P. aeruginosa. The biosynthesis method was straightforward and yielded good results without using toxic chemicals. The size distribution of the gold nanoparticles synthesized by P. aeruginosa at higher temperatures was larger than that synthesized at lower temperatures. The GNPs morphology was isotropic at various temperatures. With an increase in the temperature, the stability of the GNPs decreased. The absorption and fluorescence spectra accorded well with the size distribution of the particles, with the nanoparticle size increasing as the absorption and fluorescence increased too. The optical properties of the GNPs observed in the study accorded well with the scanning electron microscopy (SEM) observations. The visible photoluminescence (PL) around 435 nm indicated the possible use of the obtained colloids, which consisted of GNPs and capping biomaterial, in therapeutic applications. Moreover, the synthesized GNPs showed good antibacterial activity toward E. coli indicating their potential in biological applications.

Gardenia jasminoides extract-capped gold nanoparticles reverse hydrogen peroxide-induced premature senescence

This study reports a green approach for synthesis of gold nanoparticles using Gardenia jasminoides extract, and specifically, can potentially enhance anti senescence activity. Biological synthesis of gold nanoparticles is ecofriendly and effective for the development of environmentally sustainable nanoparticles compared with existing methods. Here, we developed a simple, fast, efficient, and ecofriendly approach to the synthesis of gold nanoparticles by means of a Gardenia jasminoides extract. These G. jasminoides extract-capped gold nanoparticles (GJ-GNPs) were characterized by UV–vis, high resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), and Furrier transform infrared spectroscopy (FT-IR). The synthesized GJ-GNPs turned red and showed maximal absorbance at 540nm. Thus, GJ-GNPs were synthesized successfully. We hypothesized that GJ-GNPs would protect ARPE19 cells from hydrogen peroxide-induced premature senescence. SA-β-gal activity was elevated in hydrogen peroxide-treated cells, however, this effect was attenuated by GJ-GNP treatment. Moreover, compared with the normal control, hydrogen peroxide treatment significantly increased lysosome content of the cells and production of reactive oxygen species (ROS). GJ-GNPs effectively attenuated the increase in lysosome content and ROS production in these senescent cells. According to cell cycle analysis, G2/M arrest was promoted by hydrogen peroxide treatment in ARPE19 cells, however, this change was reversed by GJ-GNPs. Western blot analysis showed that treatment with GJ-GNPs increased the expression of p53, p21, SIRT3, HO-1, and NQO1 in senescent cells. Our findings should advance the understanding of premature senescence and may lead to therapeutic use of GJ-GNPs in retina-related regenerative medicine.

Biosynthesis and Biomedical Applications of Gold Nanoparticles Using Eclipta prostrata Leaf Extract

This study reports the biological synthesis of gold nanoparticles (AuNPs) by the reduction of HAuCl4 by using of Eclipta prostrata leaf extract as the reducing and stabilizing agent. AuNPs were characterized using Ultraviolet–visible (UV-vis) spectroscopy, X-ray diffraction (XRD), Fourier Transform-Infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM), High Resolution-Transmission Electron Microscopy (HRTEM), and Energy Dispersive X-ray analysis (EDAX). The UV-visible spectrum of the synthesized AuNPs showed surface plasmon resonance (SPR) around 534 nm. The face-centered cubic (FCC) structure of the AuNPs was confirmed by XRD peaks at 38.10°, 44.13°, 64.43°, and 77.32°, which correspond to (111), (200), (220), and (311) miller indices, respectively, with clear circular spots in the selected area electron diffraction (SAED). FTIR measurements showed the AuNPs having a coating of phenolic compounds, indicating a possible role of biomolecules responsible for capping and efficient stabilization of the AuNPs. The HRTEM images determined the particles are spherical, hexagonal, and triangular in shape, with an average size of 31 ± 1.6 nm. The synthesized AuNPs show good antibacterial, antioxidant, and cytotoxic activity. The outcomes of this study indicate that these nanoparticles could be effectively utilized in pharmaceutical, biotechnological, and biomedical applications.

Antibacterial, antibiofilm and cytotoxic effects of Nigella sativa essential oil coated gold nanoparticles

This study reports the biological synthesis of gold nanoparticles using essential oil of Nigella sativa (NsEO-AuNPs). The synthesized NsEO-AuNPs were characterized by UV–visible spectra, X-ray diffraction (XRD), FTIR and Transmission electron microscopy (TEM). UV–vis spectra of NsEO-AuNPs showed strong absorption peak at 540 nm. The X-ray diffraction analysis revealed crystalline nature of nanoparticle with distinctive facets (111, 200, 220 and 311 planes) of NsEO-AuNPs. The FTIR spectra recorded peaks at 3388, 2842, 1685, 1607, 1391 and 1018 cm−1. TEM studies showed the spherical shape of nanoparticles and the particle size ranges between 15.6 and 28.4 nm. The antibacterial activity of NsEO-AuNPs was greater against Gram positive Staphylococcus aureus MTCC 9542 (16 mm) than Gram negative Vibrio harveyi MTCC 7771 (5 mm) at the concentration of 10 μg ml−1. NsEO-AuNPs effectively inhibited the biofilm formation of S. aureus and V. harveyi by decreasing the hydrophobicity index (78% and 46% respectively). The in-vitro anti-lung cancer activity confirmed by MTT assay on the cell line of A549 carcinoma cells showed IC50 values of bulk Au at 87.2 μg ml−1, N. sativa essential oil at 64.15 μg ml−1 and NsEO-AuNPs at 28.37 μg ml−1. The IC50 value showed that NsEO-AuNPs was highly effective in inhibiting the A549 lung cancer cells compared to bulk Au and N. sativa essential oil.

Improved biological synthesis of gold nanoparticles using methanobactin

The present study reported a novel approach for the green synthesis of gold nanoparticles (AuNPs) by using methanobactin (Mb) from the spent medium of Methylosinus trichosporium 3011. This paper explored the synthesis of AuNPs under different Mb concentrations, temperatures, and reaction times. The biosynthesized AuNPs were characterized by using UV–Visible spectroscopy, fluorescence spectroscopy, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FTIR). Comparing with the previous research using hydroquinone as an extra electron donor to synthesis of AuNPs, this research was the first to show that rising temperature improved the formation rate of AuNPs in a higher concentration of Mb itself. The formation of AuNPs was confirmed by surface plasmon resonance using UV–Visible spectrophotometry. Fluorescence spectroscopy experiments revealed that Mb sample showed three prominent peaks. In addition, the fluorescence exhibited by Mb was rapidly quenched upon addition of HAuCl4. According to the image analysis performed on a TEM micrograph, the obtained AuNPs were predominantly spherical with an average size of 19.3 ± 5.5 nm. XPS analysis demonstrated that Mb molecules reduced Au(III) to Au(0). FTIR spectrum confirmed the involvement of biomass groups in capping and reduction of AuNPs, which increased the stability of the synthesized AuNPs.

Biosynthesis of gold nanoparticles using Sargassum swartzii and its cytotoxicity effect on HeLa cells

In this investigation, biological synthesis of gold nanoparticles (AuNPs) using Sargassum swartzii and its cytotoxicity against human cervical carcinoma (HeLa) cells is reported. The biological synthesis involved the reduction of chloroauric acid led to the formation of AuNPs within 5min at 60°C and the formation of AuNPs was confirmed using UV–vis spectrophotometer. The AuNPs were stable; spherical in shape with well-defined dimensions, and the average size of the particle is 35nm. A zeta potential value of −27.6mV revealed synthesized AuNPs were highly stable. The synthesized AuNPs exhibited a dose-dependent cytotoxicity against human cervical carcinoma (HeLa) cells. Furthermore, induction of apoptosis was measured by DAPI (4′,6-Diamidino-2-phenylindole dihydrochloride) staining.

Marine algae-mediated synthesis of gold nanoparticles using a novel Ecklonia cava.

In the present study, we report rapid biological synthesis of gold nanoparticles (Au NPs) using a novel marine brown alga Ecklonia cava (Family: Lessoniaceae) by the reduction of chloroauric acid. The formation of Au NPs reaction was complete within 1 min at 80 °C and physiochemically characterized with different analytical techniques. FTIR spectroscopy revealed that Au NPs were functionalized with biomolecules that have primary amine group, hydroxyl group and other stabilizing functional groups. X-ray diffraction pattern showed high purity and face-centered cubic structure of Au NPs. Microscopy results showed that these Au NPs are formed with shapes like spherical and triangular with an average size of 30 ± 0.25 nm. Synthesized Au NPs showed good antimicrobial and biocompatibility with human keratinocyte cell line. Thus, physiochemical characteristic results suggest that Au NPs will have promising biomedical applications in different area such as drug delivery, tissue engineering, biosensor, etc.

Biological synthesis of gold nanoparticles by the xylotrophic basidiomycete Lentinula edodes

Biological synthesis of gold nanoparticles by the xylotrophic basidiomycete Lentinula edodes