Green Synthesis Of Gold Nanoparticles Research Articles

Green Synthesis of Gold Nanoparticles from Polygahatous Polysaccharides and Their Anticancer Effect on Hepatic Carcinoma through Immunoregulation

Green Synthesis of Gold Nanoparticles from Polygahatous Polysaccharides and Their Anticancer Effect on Hepatic Carcinoma through Immunoregulation

Enhanced photocatalytic degradation of organic pollutants by green-synthesized gold nanoparticles using polysaccharide for environmental remediation

The recent rise in textile dye wastewater discharge into the environment has detrimental effects on living organisms and human health. The present study reports a facile approach to green-synthesized AuNPs employing sesbania gum for catalytic and photocatalytic degradation of organic pollutants. The obtained AuNPs were characterized by various techniques such as UV–vis, FT-IR, SEM, TEM, AFM, zeta potential, LC-MS, and XPS. The XRD patterns revealed a highly crystalline and face-centered cubic structure. XPS and EDX analysis defined the chemical composition and product purity of SBG-AuNPs. Photocatalytic degradation of hazardous dyes congo red and safranin-O using SBG-AuNPs showed a rapid decomposition rate with 94.69 % under visible light irradiation. The effect of pH, dye concentration, and catalyst dose on photodegradation and recyclability was also studied. The kinetic plots were used to calculate the rate constant, showing a pseudo-first-order reaction. Scavenger trap experiments confirmed the role of h+ and superoxide(.O2−) as active species, and LCMS analysis was used to identify the degradation intermediates. The catalytic reduction of SBG–AuNPs was studied for brilliant green (BG) and methylene blue (MB) in the presence of NaBH4, resulting the degradation efficiency of 90.37 % and 84.52 %, respectively. This study presents an innovative approach for designing highly efficient photocatalysts for environmental remediation and wastewater treatment from textile dyes.

Green synthesis of gold nanoparticles via Artocarpus odoratissimus peel extract for potential applications of optical filter and catalytic degradation

Gold nanoparticles (Au NPs) were synthesized via a green synthesis method, utilizing the peel extract of Artocarpus odoratissimus as both the reducing and capping agent. This study investigates the impact of peel extract concentration (ranging from 0.002 to 0.012 g/mL) and reaction temperature (including room temperature, 45 °C, and 75 °C) on the properties of the synthesized Au NPs. Various characterization techniques, such as UV–Visible spectrophotometry, transmission electron microscopy (TEM), Fourier Transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), and zeta potential analysis, were employed to analyze the synthesized samples. UV–Visible spectroscopy revealed absorption peaks of the Au NPs around 533–537 nm, varying with synthesis parameters, while TEM analysis indicated particle sizes ranging from 12 to 25 nm. XRD analysis confirmed the formation of Au NPs, with diffraction peaks aligning well with the standard. FTIR analysis suggested interactions between phytochemicals and Au NPs, contributing to their reduction and size control. The synthesized Au NPs exhibited remarkable optical filtering capability, with up to 87 % transmittance in the 751–1126 nm spectral range and significant absorbance in the lower wavelength region (300–751 nm). Additionally, catalytic studies revealed that Au NPs accelerated the degradation of rhodamine B dye, 0.0795 min−1, compared to 0.0445 min−1 without Au NPs. These findings underscore the potential of Au NPs for use in hybrid photovoltaic-thermal systems as filters, where transmitted light can be harvested for photovoltaic energy generation while absorbed light can be utilized for the thermal aspect. Moreover, Au NPs offer promise for improving wastewater quality by enhancing pollutant degradation.

Green Synthesis of Gold Nanoparticles Using Liquiritin and Other Phenolics from Glycyrrhiza glabra and Their Anti-Inflammatory Activity.

Phenolic compounds are the main phytochemical constituents of many higher plants. They play an important role in synthesizing metal nanoparticles using green technology due to their ability to reduce metal salts and stabilize them through physical interaction/conjugation to the metal surface. Six pure phenolic compounds were isolated from licorice (Glycyrrhiza glabra) and employed in synthesizing gold nanoparticles (AuNPs). The isolated compounds were identified as liquiritin (1), isoliquiritin (2), neoisoliquiritin (3), isoliquiritin apioside (4), liquiritin apioside (5), and glabridin (6). The synthesized AuNPs were characterized using UV, zeta sizer, HRTEM, and IR and tested for their stability in different biological media. The phenolic isolates and their corresponding synthesized NP conjugates were tested for their potential in vitro cytotoxicity. The anti-inflammatory effects were investigated in both normal and inflammation-induced settings, where inflammatory biomarkers were stimulated using lipopolysaccharides (LPSs) in the RAW 264.7 macrophage cell line. LPS, functioning as a mitogen, promotes cell growth by reducing apoptosis, potentially contributing to observed outcomes. Results indicated that all six pure phenolic isolates inhibited cell proliferation. The AuNP conjugates of all the phenolic isolates, except liquiritin apioside (5), inhibited cell viability. LPS initiates inflammatory markers by binding to cell receptors and setting off a cascade of events leading to inflammation. All the pure phenolic isolates, except isoliquiritin, neoisoliquiritin, and isoliquiritin apioside inhibited the inflammatory activity of RAW cells in vitro.

Hymenaea courbaril resin-mediated gold nanoparticles as catalysts in organic dyes degradation and sensors in pharmaceutical pollutants

In this study, green synthesis of gold nanoparticles (AuNPs) using aqueous extract from Hymenaea courbaril resin (HCR) is reported. The successful formation, functional group involvement, size, and morphology of the subject H. courbaril resin mediated gold nanoparticles (HCRAuNPs) were confirmed by Ultra Violet-Visible (UV–vis) spectroscopy, Fourier-Transform Infrared spectroscopy (FTIR), and Transmission Electron Microscopy (TEM) techniques. Stable and high yield of HCRAuNPs was formed in 1:15 (aqueous solution: salt solution) reacted in sunlight as indicated by the visual colour change and appearance of surface Plasmon resonance (SPR) at 560 nm. From the FT-IR results, the phenolic hydroxyl (–OH) functional group was found to be involved in synthesis and stabilization of nanoparticles. The TEM analysis showed that the particles are highly dispersed and spherical in shape with average size of 17.5 nm. The synthesized HCRAuNPs showed significant degradation potential against organic dyes, including methylene blue (MB, 85 %), methyl orange (MO, 90 %), congo red (CR, 83 %), and para nitrophenol (PNP, 76 %) up to 180 min. The nanoparticles also demonstrated the effective detection of pharmaceutical pollutants, including amoxicillin, levofloxacin, and azithromycin in aqueous environment as observable changes in color and UV–Vis spectral graph.

Green synthesis of gold nanoparticles using macroalgae Halimeda macroloba extract and their photocatalytic degradation of methylene blue and methyl orange

AbstractGreen synthesis of gold nanoparticles (AuNPs) is gaining attention of researchers because of their varieties of biomedical and environmental applications. This study reported the novel eco‐friendly synthesis of AuNPs using green macroalgae Halimeda macroloba (HM) extract and evaluate their photocatalytic potential. The green synthesized H. macroloba mediated gold nanoparticles (HM‐AuNPs) was characterized using UV–visible spectrophotometry, Fourier‐transform infrared (FT‐IR) spectroscopy, transmission electron microscope (TEM), scanning electron microscope‐energy dispersive spectroscopy, x‐ray photoelectron spectroscopy (XPS), and particle size distribution (PSD) anlaysis. The UV–visible spectrum shows a sharp intense plasmonic resonance peak at 543 nm. The bioactive compounds present in HM were primarily responsible for the biological reduction of gold ions validated by FT‐IR analysis. XRD analysis proved the crystalline face centered cubic structure of the HM‐AuNPs. The average particle size of 18.72 nm and morphological evidences were obtained from the images from TEM. The metallic form of biosynthesised HM‐AuNPs was confirmed by XPS results with a distinctive binding energy. The photocatalytic degradation ability of the green synthesized HM‐AuNPs was investigated against the methylene blue (MB) and methylene orange (MO) dyes under sunlight irradiation. The HM‐AuNPs exhibited 97.23% and 89.91% photocatalytic activity against MB and MO after 90 min of exposure to sunlight, respectively. The overall results of this research indicate that H. macroloba mediated HM‐AuNPs can be used as an effective option for the degradation of industrial dyes.

Green synthesis of gold nanoparticles from the aqueous extracts of Sphagneticola trilobata (L.) J.F Pruski as anti-breast cancer agents

The invasive plant, Sphagneticola trilobata (L.) J. F. Pruski, has been known for its bioactivities and used to synthesize gold nanoparticles (AuNPs). Nonetheless, previous research has not directly compared the effectiveness of the plant parts in producing the AuNPs. The objective of this study was to compare the effectiveness of the flower and leaf of S. trilobata in synthesizing AuNPs. S. trilobata leaves and flowers were separately extracted using distilled water at 60°C for 30 min. The leaf and flower extracts were mixed with the HAuCl. 3H2O and heated to 60°C for 30 min to yield AuNPs-ALSt and AuNPs-AFSt, respectively. AuNPs were also prepared using trisodium citrate (Na3C6H5O7) as a control. The resultant AuNPs were characterized using an ultraviolet-visible spectrophotometer, particle size analyzer, and scanning electron microscope. Antioxidant activity was evaluated based on 1-diphenyl-2-picrylhydrazyl (DPPH) inhibition and anticancer activity– 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide assay against MCF-7 cells. The AuNPs-ALSt and AuNPs-AFSt were revealed to have better stability and smaller particle diameters. AuNPs-ALSt and AuNPs-AFSt had average particle diameters of 11.86 ± 3.37 and 34.86 ± 23.56 nm, respectively. Agglomeration was predominantly observed in AuNPs synthesized using the flower or leaf extract as stipulated to be affected by the insufficient capping agent and intense hydrolytic reaction. AuNPs-AFSt had higher DPPH antioxidant activity than AuNPs-ALSt with half-maximal inhibitory concentrations of IC50 123.44 and 168.83 ppm, respectively. Both AuNPs-ALSt and AuNPs-AFSt could inhibit 80% growth of the MCF-7; however, at lower concentrations, inhibitory effects were more pronounced in AuNPs-AFSt. Aqueous extracts of S. trilobata flowers and leaves could be used to synthesize AuNPs, whereas the former yielded AuNPs with higher biological activities.

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).

Green synthesis of gold nanoparticles obtained from Punica granatum flower extract for phytochemical determination and antibacterial activity

Numerous biomedical applications such as biological detection, drug delivery, diagnostic imaging and tissue engineering, have incorporated nanotechnology. Parts of the pomegranate (Punica granatum) flower are known to have strong antibacterial properties. In this study, the anti-susceptibility test was used to look into the green synthesis of gold nanoparticles using Punica granatum and the inhibitory effect of these particles. According to the current study, prepared AuNPs were evaluated using a variety of methods including UV-visible spectrophotometry, FTIR, SEM and GC-MS to identify the phytochemicals. The bacterial and fungal species Candida albicans and Malassezia furfur that are inhibited by the synthetic colloidal gold nanoparticles made with Punica granatum flower extract include Escherichia coli, Pseudomonas, Staphylococcus, Klebsiella pneumoniae and Protea. In this work, we describe a simple, quick and reproducible method for the environmentally friendly synthesis of AuNPs without the need for expensive reducing agents. Simple incubation of a flower extract with aqueous gold ions at ambient temperature resulted in ‘medium monodisperse’ nanoparticles, suggesting that the plant extract acted as a strong reducing agent.

Green synthesis, characterization, anti-cancer and antimicrobial activity of AuNPs extracted from Euphorbia antiquorum stem and flower: Experimental and theoretical calculations

Green nanoparticles derived from medicinal plants have attained popularity in recent years. Gold nanoparticles, with their distinct biological properties, are being investigated. Several studies have shown that gold nanoparticles are effective in anticancer treatments. In this study, Euphorbia antiquorum (EA) extract was used in the green synthesis of gold nanoparticles. The gold nanoparticles (EA-AuNps) were studied with ultraviolet–visible spectroscopy, high-resolution transmission electron microscopy (HR-TEM), energy-dispersive X-ray spectroscopy (EDS), X-ray powder diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). The antimicrobial and antioxidant activity of EA-AuNps were assessed and investigated. The EA-AuNps were tested against the MCF-7 breast cancer cell line. The main chemical components of the Euphorbia antiquorum plant include antiquol, camelliol, euphol, euphorbol, ingenol, isohelianol, and taraxerol. These molecules were optimized using density functional theory/B3LYP functional-6-311G** basis sets, and their physical and chemical properties were determined & discussed. Furthermore, the optimized molecules have been docked against Vascular endothelial growth factor receptor-2 (VGEFR-2), Extracellular signal-regulated kinase-2 (ERK-2), and Tumor necrosis factor receptor-1 (TNFR-1). The results suggest that euphol and euphorbol could be among the most potent macromolecule inhibitors.

Chemical and green synthesis of gold nanoparticles for mRNA delivery in vitro

Nanotechnology has paved the way for novel treatment strategies for diseases such as cancer. While chemical synthesis of nanoparticles (NPs) can introduce toxic and expensive reducing reagents, green synthesis offers an alternative with dual reducing and capping properties. Curcumin exhibits favourable pharmacological properties, enabling synergism with the therapeutic cargo. This study aimed to compare green and chemically synthesised gold NPs for the delivery of FLuc-mRNA in vitro. Chemical and green synthesised AuNPs were produced using trisodium citrate and curcumin, respectively, and functionalised with poly-L-lysine (PLL) and polyethylene glycol (PEG). The NP:mRNA nanocomplexes were characterised using nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM), Fourier transform infrared (FTIR), and UV–visible spectroscopy. Various mRNA binding studies assessed the optimal mRNA binding, compaction, and protection of the mRNA. All AuNPs were small (<150 nm) and had good colloidal stability, mRNA binding, and protection. The MTT (3-[4,5-dimethylthiazol-2-yl]-2.5-diphenyltetrazolium bromide) assay showed favourable cell viability, with significant transgene expression noted using the luciferase reporter gene assay. Higher transfection was achieved in the human cervical carcinoma (HeLa) than in the breast adenocarcinoma (MCF-7) and embryonic kidney (HEK293) cells. Both chemically and curcumin-synthesised AuNPs displayed similar activity in all cells, with curcumin-capped AuNPs marginally better at the same concentration.

Green-synthesized gold nanoparticles induce adaptation in photosynthetic responses, sugar and nitrogen metabolism, and seed yield of salt-stressed mustard plants

Green-synthesized gold nanoparticles induce adaptation in photosynthetic responses, sugar and nitrogen metabolism, and seed yield of salt-stressed mustard plants

Selective Colorimetric Detection of Pb(II) Ions by Using Green Synthesized Gold Nanoparticles with Orange Peel Extract

Gold nanoparticles (AuNPs) were prepared by using a green approach that employed orange (citrus sinensis) peel water extract (OPE) as a reducing agent. In this case, the organic compounds present in orange peel were able to reduce Au(III) to Au(0) and, at the same time, to act as a capping agent, functionalizing the surface of the AuNPs, stabilizing them in a water solution. This “green” approach valorizes orange peel waste as a resourceful material and makes the synthetic process of AuNPs more environmentally sustainable, safe, and economically feasible than the traditional methods. The obtained gold nanoparticles (AuNPs@OPE) were characterized by FT–IR, DLS, SEM analysis, and UV–Vis spectroscopy; the latter showed a characteristic surface plasmon resonance (SPR) band at 530 nm, typical of spherical gold nanoparticles. The AuNPs@OPE were then tested as colorimetric sensors for heavy metals in water, showing an affinity and selectivity toward Pb2+. In fact, in the presence of Pb2+, the added cation favors the aggregation process, and, in this case, nanoparticles form clusters due to the interactions between Pb2+ and the carboxyl/hydroxyl groups on the surface of the AuNPs@OPE, increasing the size of the nanostructure. This process is accompanied by a change in color of the AuNPs@OPE from pink to violet, with a formation of a second, new SPR band, at a higher wavelength, relative to the aggregate formation. The colorimetric assay was tested at different times with the addition of Pb2+ ions showing different LOD values of 13.31 µM and 0.05 µM after 15 min and 90 min, respectively. The proposed colorimetric assay was also tested for analyzing Pb2+ in drinking water samples demonstrating the reliability to use AuNPs@OPE with real samples.

Green synthesis of gold nanoparticles mediated by extract of Curcuma longa under ultrasonic condition: Investigation of its application for reduction of dye pollutants and repairing the articular cartilage in an animal model of osteoarthritis of the knee

For environmental remediation, it is crucial to find effective heterogeneous catalysts that can remove organic contaminants or convert them into chemicals that are safe and even valuable. Here, we present the synthesis of a green gold-based catalyst using an extract of Curcuma longa (Au NPs@C. longa) under ultrasonic condition. This nanocatalyst demonstrated good performance for reduction of organic dyes including methyl orange, methylene blue, and 4-nitrophenol. FE-SEM in conjunction with EDS, TEM, and UV–visible spectroscopy were used to evaluate the produced nanocatalyst. The Au NPs@C. longa should show great promise for wastewater treatment since it has the advantages of good activity, good kinetics and suitable stability for dye reduction. In the orthopedic experiments, the efficacy of Au NPs@C. longa on chondrogenesis was assessed by the primary cultured chondrocytes. Western blot, PCR, and histological assays were done to follow the underlying mechanisms. We evaluated the functional recovery after Au NPs@C. longa transplantation by an osteoarthritis articular cartilage injury model in knee. In immunological section, the Au NPs@C. longa reduced the levels of TNF-α, IL-1β, MMPs, and p-p65 expression. This may be caused by adjusting cellular redox homeostasis related to the Nrf2. The data indicated the positive efficacy of Au NPs@C. longa on stimulating chondrogenesisin vitro. It was revealed that the Au NPs@C. longa application speeded up the injury-induced dysfunction recovery after 21 days. The Au NPs@C. longa application suppressed the abnormal fibrosis and angiogenesis at the injury site.

Green synthesis of gold nanoparticles using Acorus calamus leaf extract and study on their anti-alzheimer potential

Green synthesis of gold nanoparticles using Acorus calamus leaf extract and study on their anti-alzheimer potential

Anti-cancer effects of green synthesized gold nanoparticles using leaf extract of Annona muricata. L against squamous cell carcinoma cell line 15 through apoptotic pathway

Background: Oral cancer remains one of the most dreadful diseases in developing nations. Currently, there has been a rise in the prevalence of tongue squamous cell carcinoma (SCC), with a poor prognosis. The use of standard treatment approaches against oral cancer patients brings about several side effects. In recent years, nanomedicine has provided a versatile platform for developing new targeted therapeutic modalities. However, safety remains a concern in the synthesis of nanoparticles (NPs). Therefore, the present study aims to synthesize safer phytoconstituent-mediated gold NPs (AuNPs) utilizing leaf extracts of Annona muricata, where the biochemical components of the plant leaf act as the reducing and capping agents in the synthesis of NPs, and to evaluate its anti-cancer activity against SCC. Materials and Methods: In this in vitro experimental study, AuNPs were synthesized through an effective, simple, and ecologically sound green synthesis method. After characterization of these synthesized AuNPs, in vitro assays such as 3-(4, 5-dimethylthiazole2-yl)-2, 5-biphenyl tetrazolium bromide, wound healing, and clonogenic assays were carried out to investigate the anti-cancer potential of green synthesized AuNPs in the human tongue SCC cell line (SCC-15), and the possible mechanism of action was evaluated through gene and protein expression analysis of Bax, Bcl-2, and p53 genes. The results were expressed as mean ± standard deviation using Statistical Package for Social Sciences (SPSS) 20.0 software and Student's t-test was performed for experimental data. P ≤0.05 were considered statistically significant. Results: The in vitro assays demonstrated that the synthesized AuNPs are exhibiting anti-cancer activity by apoptosis of SCC-15 cells in a dose-dependent manner. Further, it also revealed a highly significant decrease in anti-apoptotic Bcl-2 gene expression, whereas pro-apoptotic genes p53 and Bax revealed a highly significant increase, which is statistically significant compared to the control (P &lt; 0.05). Conclusion: Our findings demonstrated that the AuNPs synthesized from A. muricata leaf extract could act as a novel anticancer agent, particularly against SCC, after further scrutiny.

Plasmon-based colorimetric assay using green synthesized gold nanoparticles for the detection of bisphenol A.

Herein, we report a green synthesized gold nanoparticle (AuNPs) based colorimetric detection of bisphenol A (BPA). The AuNPs were synthesized using khat leaf extract as a reducing agent by optimizing factors affecting the AuNPs synthesis, including gold precursor concentration (1mM), and reaction temperature (60°C). The AuNPs characterization was carried out using ultraviolet-visible spectrophotometry and transmission electron microscopy, and it was found spherical with an average particle size of 17.3 ± 3.7nm. A colorimetric nanosensor was developed by conjugation of bio-inspired AuNPs with BPA-specific aptamer for a quick and easy detection of BPA in plastic bottled water. The colorimetric assay relies on the strong affinity of BPA for aptamer, which causes detachment of the aptamer from the AuNPs surface in the presence of BPA inducing AuNPs aggregation. To achieve the colorimetric detection of BPA, the concentrations of NaCl and aptamer were optimized. The detection of BPA was monitored visually using a naked eye, as well as quantitatively using an ultraviolet-visible spectrophotometer. The method visual limit of detection (LOD) was determined to be 0.1ng/mL and reached 0.09ng/mL using ultraviolet-visible spectrophotometer. The method demonstrated very good linearity (R2 = 0.9986) in the range of 0.1-100ng/mL. The proposed method showed high sensitivity to BPA detection in plastic bottled water with 86.7-98.0%, recovery. Therefore, the proposed colorimetric nanosensor can be used for determination of BPA in plastic bottled waters with reliable performance at lower concentrations.

Green synthesis of gold nanoparticles from Coleus scutellarioides (L.) Benth leaves and assessment of anticancer and antioxidant properties

Gold nanoparticles (AuNPs) have gained significant attention in the field of biomedicine due to their versatile potential and diverse applications. In this study, AuNPs were biologically synthesized using the leaf extract of Coleus scutellarioides (L.) Benth to explore the in vitro anticancer and antioxidant properties. The synthesized AuNPs underwent thorough characterization through various analyses, the UV–Visible Spectroscopy (UV–Vis) of the AuNPs displayed a peak at 532 nm, indicating the occurrence of surface plasmon resonance. The crystalline structure of the AuNPs was confirmed by analyzing the X-ray Diffraction pattern (XRD). Moreover, Transmission Electron Microscopy (TEM) analysis revealed a spherical morphology for the AuNPs, with an average particle size of 40.10 nm, consistent with the measurements obtained from Dynamic light scattering (DLS). After that, the biological performance of those biomolecules functionalized AuNPs was studied. This study investigated the potential cytotoxic effects of synthesized AuNPs using the MTT assay. The assay was employed to evaluate the cell viability against the human breast cancer cell line (MDA-MB-231) compared to the human foreskin fibroblast cell line (Hs-27), with concentrations ranging from 7.5 to 60 µg/ml over 24 h. The study findings reveal a concentration-dependent impact of synthesized AuNPs on MDA-MB-231 cells. As the AuNPs concentration increases, there is a corresponding increase in the inhibition of MDA-MB-231 cells, reaching an IC50 value of 36.10 µg/ml within a 24-hour period. Contrarily, the synthesized AuNPs exhibited no apparent toxicity against the noncancerous normal Hs-27 cells. Furthermore, the antioxidant efficacy of AuNPs was evaluated through a free radical scavenging DPPH assay. These findings suggest the potential of Coleus scutellarioides (L.) Benth leaf extract as an effective bio-reductant for synthesizing stable AuNPs with anticancer activity and antioxidant properties.

Green synthesis of gold nanoparticles from the extract of Crocus sativus to study the effect of antidepressant in adolescence and to observe its aggressive and impulsive behavior in rat models

Depression is a unipolar condition caused by a brain monoamine deficit that affects emotion, thinking, and function. Depression treatments involve limitations such poor absorption, a delay in therapeutic efficacy, unwanted side effects, and high-dose toxicity. A simple, affordable, clean, non-toxic, and environmentally friendly nanoparticle manufacturing method was used to fix this. This research created C.sativus gold nanoparticles (CS-AuNPs) from Crocus sativus extract and auric chloride (HAuCl4). CS-AuNPs was spherical, 11–20 nm in size, and 550 nm absorbent after UV–vis, XRD, FTIR, SEM, and TEM analysis. Saffron action is increased using gold nanoparticles, a non-toxic drug delivery vehicle. Crocins, crocetin, and safranal are important antidepressants. Crocus sativus has been shown to effectively reduce proinflammatory cytokines mRNA expression (IL-1β, IL-6, and TNF-α) and inhibit NF-κB activation. With an IC50 of 256 μg/ml for DPPH, IC50 of 300 μg/ml for NBT assay and 90 % cell survival in cytotoxicity tests, this chemical is safe and effective as an antidepressant. The new study showed that C.sativus has therapeutic promise and that converting it from extract to nanoparticles will benefit depression treatment.

The application of bacteria-derived dehydrogenases and oxidases in the synthesis of gold nanoparticles.

In this work the green synthesis of gold nanoparticles (Au-NPs) using the oxidoreductive enzymes Myriococcum thermophilum cellobiose dehydrogenase (Mt CDH), Glomerella cingulata glucose dehydrogenase (Gc GDH), and Aspergillus niger glucose oxidase (An GOX)) as bioreductants was investigated. The influence of reaction conditions on the synthesis of Au-NPs was examined and optimised. The reaction kinetics and the influence of Au ions on the reaction rate were determined. Based on the kinetic study, the mechanism of Au-NP synthesis was proposed. The Au-NPs were characterized by UV-Vis spectroscopy and transmission electron microscopy (TEM). The surface plasmon resonance (SPR) absorption peaks of the Au-NPs synthesised with Mt CDH and Gc GDH were observed at 535nm, indicating an average size of around 50nm. According to the image analysis performed on a TEM micrograph, the Au-NPs synthesized with Gc GDH have a spherical shape with an average size of 2.83 and 6.63nm after 24 and 48h of the reaction, respectively. KEY POINTS: • The Au NPs were synthesised by the action of enzymes CDH and GDH. • The synthesis of Au-NPs by CDH is related to the oxidation of cellobiose. • The synthesis of Au-NPs by GDH was not driven by the reaction kinetic.