Synthesis Of Gold Nanoparticles Research Articles

Gold Nanoparticles in Nanobiotechnology: From Synthesis to Biosensing Applications.

Nanobiotechnology has ushered in a new era of scientific discovery where the unique properties of nanomaterials, such as gold nanoparticles, have been harnessed for a wide array of applications. This review explores gold nanoparticles' synthesis, properties, and multidisciplinary applications, focusing on their role as biosensors. Gold nanoparticles possess exceptional physicochemical attributes, including size-dependent optical properties, biocompatibility, and ease of functionalization, making them promising candidates for the development of biosensing platforms. The review begins by providing a comprehensive overview of gold nanoparticle synthesis techniques, highlighting the advantages and disadvantages of various approaches. It then delves into the remarkable properties that underpin their success in biosensing, such as localized surface plasmon resonance and enhanced surface area. The discussion also includes the functionalization strategies that enable specific binding to biomolecules, enhancing the sensitivity and selectivity of gold-nanoparticle-based biosensors. Furthermore, this review surveys the diverse applications of gold nanoparticles in biosensing, encompassing diagnostics, environmental monitoring, and drug delivery. The multidisciplinary nature of these applications underscores the versatility and potential of gold nanoparticles in addressing complex challenges in healthcare and environmental science. The review emphasizes the pressing need for further exploration and research in the field of nanobiotechnology, particularly regarding the synthesis, properties, and biosensing applications of gold nanoparticles. With their exceptional physicochemical attributes and versatile functionalities, gold nanoparticles present a promising avenue for addressing complex challenges in healthcare and environmental science, making it imperative to advance our understanding of their synthesis, properties, and applications for enhanced biosensing capabilities and broader scientific innovation.

An Investigation into the Additional Potential of Iron-Reducing Bacteria Harnessed for Gold Nanoparticle Synthesis

Introduction: Soil bacteria that synthesize varying metallic NPs are underreported, even though there is a promising mechanism in the bio-reduction of gold salts and the synthesis of gold nanoparticles by different bacterial species. Objective: This study aimed to explore the ancillary potential of some soil microbes obtained from a metal fabricating workshop for gold nanoparticles (AuNPs) synthesis. Methods: To evaluate the usefulness of these soil microbes, 1mM chloroauric acid (HAuCl4.4H2O) was bio-reduced using the wet biomass of these bacterial cells and characterized with UV-Vis spectrophotometer, Fourier Transform Infra-red (FTIR), Scanning Electron Microscope [SEM), Energy Dispersive X-ray (EDX), and X-ray Diffractometer (XRD). Results: The study findings showed that the studied bacterial isolates synthesized AuNPs with absorbance peaks within the range of 500 and 600 nm. The FTIR analysis showed the involvement of O-H, N-H, and C=O stretch of alcohol, amine, and amide groups, respectively. The SEM images analyzed with Image J reported a mean area size between 17-184 nm. The EDX showed Klebsiella africana (C11), and Bacillus subtilis (A12) had the lowest (7.32%) and highest (51.26 %) weight percentages of AuNPs, respectively. Conclusion: Gold nanoparticles have been found most appropriate for several novel applications, and this work has provided further understanding of the capacity of naturally occurring bacteria to be non-selective in the bio-reduction of gold salts, hence expanding their potential uses.

Green synthesized extracts/Au complex of Phyllospongia lamellosa: Unrevealing the anti-cancer and anti-bacterial potentialities, supported by metabolomics and molecular modeling

The anti-cancer and anti-bacterial potential of the Red Sea sponge Phyllospongia lamellosa in its bulk (crude extracts) and gold nanostructure (loaded on gold nanaoparticles) were investigated. Metabolomics analysis was conducted, and subsequently, molecular modeling studies were conducted to explore and anticipate the P. lamellosa secondary metabolites and their potential target for their various bioactivities. The chloroformic extract (CE) and ethyl acetate extract (EE) of the P. lamellosa predicted to include bioactive lipophilic and moderately polar metabolites, respectively, were used to synthesize gold nanoparticles (AuNPs). The prepared AuNPs were characterized through transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), and UV–vis spectrophotometric analyses. The cytotoxic activities were tested against MCF-7, MDB-231, and MCF-10A. Moreover, the anti-bacterial, antifungal, and anti-biofilm activity were assessed. Definite classes of metabolites were identified in CE (terpenoids) and EE (brominated phenyl ethers and sulfated fatty amides). Molecular modeling involving docking and molecular dynamics identified Protein-tyrosine phosphatase 1B (PTP1B) as a potential target for the anti-cancer activities of terpenoids. Moreover, CE exhibited the most powerful activity against breast cancer cell lines, matching our molecular modeling study. On the other hand, only EE was demonstrated to possess powerful anti-bacterial and anti-biofilm activity against Escherichia coli. In conclusion, depending on their bioactive metabolites, P. lamellosa-derived extracts, after being loaded on AuNPs, could be considered anti-cancer, anti-bacterial, and anti-biofilm bioactive products. Future work should be completed to produce drug leads.

Nanostructural modulation of Schottky barrier in Au/α-MoO3 heterojunction via Au nanoparticle size control

Metal-semiconductor systems, particularly those incorporating metallic nanoparticles, have garnered significant attention due to their charge transport properties and potential in solid-state applications. Thus, this study focuses on the synthesis of MoO3 microstructures through thermal oxidation, followed by the synthesis of gold nanoparticles (AuNPs) via post-thermal treatment of an Au-coated film. We systematically investigated the effect of annealing temperatures ranging from 400 °C to 700 °C on the size of the AuNPs. Utilizing techniques such as X-ray diffraction, electron microscopy, reflectance, and X-ray photoelectron spectroscopy (XPS), the physical and chemical properties of the AuNPs/MoO3 heterojunction were characterized. Findings reveal a direct correlation between the size of AuNPs and the Schottky barrier height (SBH) in the Au/MoO3 system. By considering factors such as defects, impurities, lattice mismatch, and Au diffusion—referred to as the alpha adjustment—we established that smaller AuNPs foster lower SBH values in the heterostructures. The adjusted SBH for AuNPs with diameters of 81.90 nm ± 7.21 nm, 99.44 nm ± 9.47 nm, 134.96 nm ± 15.40 nm, and 459.99 nm ± 42.63 nm resulted in a value of 0.2 eV, 0.37 eV, 1.26 eV, and 3.61 eV, respectively.

Single laser synthesis of gold nanoparticles-polypyrrole-chitosan on laser-induced graphene for ascorbic acid detection

The simultaneous synthesis of gold nanoparticles (AuNPs) and graphene by laser ablation was demonstrated. The in-situ synthesis was performed by laser ablation of a polymer substrate covered with a gold precursor dispersion. The gold precursor was prepared in a copolymer solution of pyrrole (Py) and chitosan (Chi) to improve the nucleation of gold embedded on the laser-induced graphene electrode (LIGE). The morphology of AuNPs-pPy-Chi/LIGE was studied by scanning electron microscopy and characterized electrochemically by cyclic voltammetry. A comprehensive investigation of the electrochemical and physical features of the AuNPs-pPy-Chi/LIGE was carried out. The parameters of differential pulse voltammetry were adjusted to enhance the response to ascorbic acid (AA). The AuNPs-pPy-Chi/LIGE produced two linear ranges: from 0.25 to 5.00 and 5.00–25.00 mmol L−1. The limit of detection was 0.22 mmol L−1. Hundreds of electrodes were tested to demonstrate the excellent reproducibility of the AuNPs-pPy-Chi/LIGE fabrication. Overall, the proposed electrode allows the successful detection of AA in orange juice products with acceptable accuracy (recoveries = 97 ± 2 to 109.1 ± 0.7). The preparation strategy of the proposed AuNPs-pPy-Chi/LIGE could be adapted to detect other compounds or biomarkers.

A facile green synthesis of gold nanoparticles using Canthium parviflorum extract sustainable and energy efficient photocatalytic degradation of organic pollutants for environmental remediation

Organic dye and nitrophenol pollution from textiles and other industries present a substantial risk to people and aquatic life. One of the most essential remediation techniques is photocatalysis, which uses the strength of visible light to decolorize water. The present study reports Canthium Parviflorum (CNP) leaf extract utilization as an effective bio-reductant for green synthesis of Au NPs. A simple, eco-friendly process with low reaction time and temperature was adopted to synthesize CNP extract-mediated Au-NPs (CNP-AuNPs). The prepared AuNPs characterization involving X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron microscopy (XPS) surface area analysis, ultraviolet–visible spectroscopy (UV–Vis). XRD results showed that the cubic-structured AuNPs had a crystallite size of 14.12 nm. Assessment of organic dyes performance in degrading brilliant green (BTG) and amido black 10B (AMB) under visible light irradiation highlights an impressive 83.25% and 86% degradation efficiency within 120 min, accompanied by a kinetic rate constant dyes was found to be 0.0828 min⁻1, BTG, and 0.0123 min⁻1, Furthermore, the reduction of 4-nitrophenol by NaBH4 using CNP-AuNPs as a catalyst demonstrated good catalytic performance and rapid degradation at 89.4%. and rate constant 0.099 min−1 followed pseudo-first-order. The LC-MS analysis identified various intermediates during the degradation of the CR dye. Radical trapping experiments suggest that photogenerated free electrons and hydroxyl radicals are crucial for degrading the amido black 10B dye The AuNPs influenced the significant factors responsible for the photocatalytic activity, such as the increase in range of absorbance, increased e− and h+ pair separation, improvement in the charge transfer process, and active site formation, which significantly enhanced the process of degradation. We found that the CNP-AuNPs could effectively remove dyes and nitrophenol from industrial wastewater.

Green synthesis of ultrafine gold nanoparticles from sweet flag (Acorus calamus) for effective anti-leukemic, anti-urolithiatic and in silico docking studies

Gold nanoparticles (AuNPs) are emerging effective biomaterials which play a vital role in the biodiversity research area due to their biocompatibility, and less toxic nature. The AuNPs of various sizes and shapes have vibrant optical features that can be utilized for a variety of imaging and therapeutic applications. Acorus calamus (A. calamus) has been used in traditional medical systems as a general tonic for centuries. It is thought to have potential benefits in the treatment of digestive disorders and respiratory problems. In Kerala, newborns were given a nanogram of (A. calamus) rhizome paste to increase oral cleanliness and improve their health and immunity. This prompted us to produce AuNPs by A. calamus and to explore their concealed pharmacological properties. In this work, we used a simple sonication method to synthesise blue-coloured AuNPs using sweet flag (A. calamus) extract, which acted as a stabilising and reducing agent at ambient temperature. The formation and morphology of the AC-AuNPs was confirmed by XRD, TEM, EDX, FT-IR and UV–vis spectral techniques. Anti-leukemic and anti-urolithiatic activities of the AC-AuNPs were also investigated. The anti-leukemic results revealed cytomorphological changes like cancer cell membrane lyses and coiling in Human myelogenous leukemia cells (K562) and exhibited IC50 at a concentration of 41.45 µg/mL. Furthermore, in vitro DNA binding assay of AC-AuNPs with calf-thymus were conducted. The anti-urolithiatic activity of AC-AuNPs suggests a dose-dependent suppression of calcium oxalate method (COM) crystals nucleation and aggregation. These results suggest that AC-AuNPs have potent antileukemic and anti-urolithiatic activities. In silico docking results revealed that eugenol, α-asarone and calamenene possess good binding scores with myeloid cell surface antigen (CD33) and estrogen receptors, respectively. In vitro anticancer and DNA binding studies have endorsed the capping nature of AC-AuNPs by these phytoconstituents, which is validated by docking analysis.

On the physical layer security of visible light communications empowered by gold nanoparticles

Visible light is a proper spectrum for secure wireless communications because of its high directivity and impermeability in indoor scenarios. However, if an eavesdropper is located very close to a legitimate receiver, secure communications become highly risky. In this paper, to further increase the level of security of visible light communication (VLC) and increase its resilience to malicious attacks, we propose to capitalize on the recently synthesized gold nanoparticles (GNPs) with chiroptical properties for circularly polarized light resulting in the phase retardation that interacts with the linear polarizer angle. GNP plates made by judiciously stacking many GNPs perform as physical secret keys. Transmitters send both the intended symbol and artificial noise to exploit the channel variation effect by the GNP plates, which is highly effective when an eavesdropper is located close to the legitimate receiver. A new, to our knowledge, VLC channel model is first developed by representing the effect of GNP plates and linear polarizers in the circular polarization domain. Based on the new channel model, the angles of linear polarizers at the transmitters and legitimate receiver are optimized considering the effect of GNP plates to increase the secrecy rate in wiretapping scenarios. Simulations verify that, when the transmitters are equipped with GNP plates, even if the eavesdropper is located right next to the legitimate receiver, insightful results on the physical layer security metrics are gained as follows: (1) the secrecy rate is significantly improved, and (2) the symbol error rate gap between the legitimate receiver and eavesdropper becomes much larger due to the chiroptical properties of GNP plates.

Harnessing barley grains for green synthesis of gold and silver nanoparticles with antibacterial potential

The continuous evolution and significance of green resources-based nanomaterials have spurred the exploration of sustainable sources for nanoparticle production. Green synthesis routes offer eco-friendly methodologies, ensuring nanoparticle stability and monodispersity, enhancing their efficiency for various applications. Notably, the thick biological corona layer surrounding nanoparticles (NPs) synthesized through green routes contributes to their unique properties. Consequently, there has been a surge in the development of NPs synthesis methods utilizing medicinal plants and diverse agricultural and waste resources. This study highlights the sustainable potential of barley grains for the synthesis of gold nanoparticles (Barley-AuNPs) and silver nanoparticles (Barley-AgNPs) as an environmentally friendly alternative, followed by NPs characterizations and their application against pathogenic bacteria: Escherichia coli UTI 89 and Pseudomonas aeruginosa PAO1. The rapid synthesis of Barley-AuNPs within 20 min and Barley-AgNPs within 30 min at 90 °C underscores the efficiency of barley as a green precursor. Characterization through advanced techniques, including SEM, TEM, EDS, AFM, DLS, FT-IR, MALDI-TOF, and sp-ICPMS, reveals the 20–25 nm size for Barley-AuNPs, while Barley-AgNPs demonstrate 2–10 nm size with spherical monodispersity. A notable contribution lies in the stability of these NPs over extended periods, attributed to a thick biological corona layer. This corona layer, which enhances stability, also influences the antimicrobial activity of Barley-AgNPs, presenting an intriguing trade-off. The antimicrobial investigations highlight the significant potential of Barley-AgNPs, with distinct minimum bactericidal concentrations (MBC) against P. aeruginosa and E. coli at 8 µg/mL. Overall, this research pioneers the use of barley grains for nanoparticle synthesis and unveils these nanoparticles' unique characteristics and potential antibacterial applications, contributing to the evolving landscape of sustainable nanotechnology.Graphic

Photothermal and radiotherapy with alginate-coated gold nanoparticles for breast cancer treatment

Radiation therapy and phototherapy are commonly used cancer treatments that offer advantages such as a low risk of adverse effects and the ability to target cancer cells while sparing healthy tissue. A promising strategy for cancer treatment involves using nanoparticles (NPs) in combination with radiation and photothermal therapy to target cancer cells and improve treatment efficacy. The synthesis of gold NPs (AuNPs) for use in biomedical applications has traditionally involved toxic reducing agents. Here we harnessed dopamine (DA)-conjugated alginate (Alg) for the facile and green synthesis of Au NPs (Au@Alg-DA NPs). Alg-DA conjugate reduced Au ions, simultaneously stabilized the resulting AuNPs, and prevented aggregation, resulting in particles with a narrow size distribution and improved stability. Injectable Au@Alg-DA NPs significantly promoted ROS generation in 4T1 breast cancer cells when exposed to X-rays. In addition, their administration raised the temperature under a light excitation of 808 nm, thus helping to destroy cancer cells more effectively. Importantly, no substantial cytotoxicity was detected in our Au@Alg-DA NPs. Taken together, our work provides a promising route to obtain an injectable combined radio enhancer and photothermally active nanosystem for further potential clinic translation.

Shape-controlled Synthesis and Bulk Refractive Index Sensitivity Studies of Gold Nanoparticles for LSPR-based Sensing

Shape-controlled Synthesis and Bulk Refractive Index Sensitivity Studies of Gold Nanoparticles for LSPR-based Sensing

Synthesis and Characterization of Gold Nanoparticles (AuNPs) from Chrozophora rottleri (Geiseler) Spreng. An Evaluation of Antioxidant and Antimicrobial Activities

This is the first report of its kind on the study. Applications for nanobiotechnology include coatings, cosmetics, packaging, biomedicine, and boosting biological activity. Given the importance of Chrozophora rottleri (Euphorbiaceae) we developed gold nanoparticles (AuNPs) economically and ecologically responsibly. In less than a minute, the color of the gold nanoparticles (AuNPs) synthesized in this work changed from yellow to wine red. Advanced methods such as UV-visible spectroscopy, Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and zeta potential (ZP) were used to study these nanoparticles. The synthesized gold nanoparticles’ anti-microbial (bacterial and fungal) and in vitro antioxidant (DPPH and H2O2) characteristics were evaluated. Standard ascorbic acid concentrations of 10, 25, 50, 75, and 100 µg/ml were used to investigate the DPPH free radical scavenging activity. The findings showed that 18.53±0.162 was the lowest percentage of inhibition and 83.62±0.785 was the greatest. Analogously, the ascorbic acid hydrogen peroxide radical scavenging (H2O2) assay revealed that the maximum % inhibition was 87.27±0.467 and the lowest was 19.52±0.225. The Agar well-diffusion method was used to examine the antibacterial effectiveness of ampicillin and synthesized gold nanoparticles (AuNPs). Four distinct concentrations (25, 50, 75, and 100 µl) were assessed in relation to several bacterial pathogens, such as Escherichia coli, Streptococcus pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus. Elevated doses of traditional Ampicillin demonstrated a progressive degree of inhibitory impact on E. coli and S. aureus, signifying heightened antimicrobial efficacy. Zones measuring 16 mm, 20 mm, 22 mm, and 25 mm were seen in ampicillin, while zones measuring 11 mm, 13 mm, 14 mm, and 16 mm were seen in E. coli The synthesized gold nanoparticles (CR-AuNPs) demonstrated increased zones of inhibition measuring 1.2 mm, 12 mm, 14 mm, and 17 mm, indicating greater antibacterial activity against S. pneumoniae. Similar to this, P. aeruginosa was inhibited by AuNPs, and the zones of inhibition measured 0.6 mm, 12 mm, 16 mm, and 18 mm. The CR-AuNPs show activity against S. aureus, E. coli, S. pneumoniae, and P. aeruginosa at a concentration of 200 µg/ml, which is the minimum inhibitory concentration (5, 10, 25, 50, 100, and 200 µg/ml). The well diffusion method was utilized to evaluate the antifungal efficacy of AuNPs and Fluconazole against Aspergillus niger. The findings showed that the zones of inhibition, which measured 12 mm, 16 mm, 21 mm, and 25 mm, gradually increased. Moreover, the zones of inhibition against Candida albicans were observed to be 13 mm, 16 mm, 18 mm, and 22 mm. At 12 mm, 15 mm, 19 mm, and 23 mm, the CR-AuNPs showed increasingly wider zones of inhibition against Aspergillus niger. Furthermore, 11 mm, 14 mm, 17 mm, and 19 mm zones of inhibition were seen in Candida albicans. The findings point to the potential for producing gold nanoparticles (AuNPs) using green synthesis methods that are both economical and ecologically benign. Moreover, this work is the first to suggest that C. rottleri may have antioxidant and antibacterial properties. As a result, this creates new chances in various fields in addition to medicines

Tricyclic microwave-assisted synthesis of gold nanoparticles for biomedical applications: combatting multidrug-resistant bacteria and fungus

BackgroundRising global mortality due to antibiotic-resistant pathogens necessitates novel antibacterial and antifungal agents. This study focuses on synthesizing gold nanoparticles (GNPs) via tricyclic microwave irradiation (TMI) to combat Multi-Drug-Resistant Bacteria and Fungus. The demand for sustainable synthesis methods has led to the exploration of TMI for GNP production.ResultsCharacterization demonstrates consistent, uniform, and dispersed GNPs with trigonal and hexagonal shapes. GNPs sized 20–55 nm exhibit superior antibacterial and antifungal activity, particularly against drug-resistant Gram-positive bacteria. Notably, GNPs display consistent efficacy against drug-resistant fungus and demonstrate potential for broad-spectrum antimicrobial applications.ConclusionTMI-synthesized GNPs, characterized by their favorable physical properties and size-dependent efficacy, show promise as effective agents against drug-resistant pathogens. Their ability to combat Gram-positive bacteria, Gram-negative bacteria, and drug-resistant fungus positions them as valuable tools in biomedical sciences. By addressing the urgent need for novel antimicrobial agents, TMI-synthesized GNPs offer a sustainable solution to the escalating global health challenge of antibiotic resistance.

Straightforward microwave-assisted synthesis of ultrasmall gold nanoparticles acnhored on reduced graphene oxide for enhanced antibacterial application

Graphene derivative materials, such as graphene oxide (GO) and reduced graphene oxide (rGO), have garnered significant attention from scientists for over two decades due to their distinctive characteristics and versatile applications across various fields, particularly in biomedical applications. Incorporating gold nanoparticles (AuNPs) into rGO sheets as rGO-Au nanocomposites further enhances its performance in biomedical applications. This study presents a rapid and efficient method for synthesizing ultrasmall AuNPs anchored on reduced graphene oxide (rGO-Au) using microwave irradiation and ascorbic acid. The optimum microwave treatment was 4 min, ensuring the highest GO reduction degree. Structural characterization by TEM reveals a distinctive architecture with ultrasmall AuNPs (average size of 2.2 nm) distributed on the rGO sheets. Interestingly, while the synthesized rGO-Au did not exhibit any antibacterial activities against both Escherichia coli and Staphylococcus aureus in disk diffusion assays, it demonstrated bacteriostatic effect at remarkably low concentrations when assessed by optical density measurement. The effective concentration of rGO-Au to inhibit E. coli growth was determined to be 2.5 ppm, while for S. aureus, it was 5 ppm, resulting in growth inhibition of 53.1% and 50.0%, respectively. These findings provide a straightforward synthesis route for rGO-Au nanocomposites and underscore the importance of AuNPs’ size and quantity in modulating antibacterial properties.

Green synthesis of gold nanoparticles by curcin from Jatropha curcas: Characterization and antibacterial activity

Green synthesis of gold nanoparticles by curcin from Jatropha curcas: Characterization and antibacterial activity

Coprisin/Compound K Conjugated Gold Nanoparticles Induced Cell Death through Apoptosis and Ferroptosis Pathway in Adenocarcinoma Gastric Cells.

Ferroptosis and apoptosis are programmed cell death pathways with distinct characteristics. Sometimes, cancer cells are aided by the induction of a different pathway, such as ferroptosis, when they develop chemoresistance and avoid apoptosis. Identifying the nanomedicine that targets dual pathways is considered as one of the best strategies for diverse cancer types. In our previous work, we synthesized gold nanoparticles (GNP) utilizing Gluconacetobacter liquefaciens in conjunction with compound K (CK) and coprisin (CopA3), yielding GNP-CK-CopA3. Here, we assessed the inhibitory effect of GNP-CK-CopA3 on AGS cells and the induction of apoptosis using Hoechst and PI, Annexin V-FITC/PI, and qRT-PCR. Subsequently, we conducted downstream proteomic analysis and molecular dynamic stimulation to identify the underlying molecular mechanisms. Our investigation of cultured AGS cells treated with varying concentrations of GNP-CK-CopA3 demonstrated the anticancer properties of these nanoparticles. Penetration of GNP-CK-CopA3 into AGS cells was visualized using an enhanced dark field microscope. Apoptosis induction was initially confirmed by treating AGS cells with GNP-CK-CopA3, as evidenced by staining with dyes such as Hoechst and PI. Additionally, mitochondrial disruption and cellular localization induced by GNP-CK-CopA3 were validated through Mito-tracker staining and transmission electron microscopy images. Annexin V-FITC/PI staining was used to distinguish early and late-stage apoptosis or necrosis based on fluorescence patterns. The gene expression of apoptotic markers indicated the initiation of cellular apoptosis. Further, proteomic analysis suggested that the treatment of GNP-CK-CopA3 to AGS cells led to the suppression of 439 proteins and the stimulation of 832 proteins. Among these, ferroptosis emerged as a significant interconnected pathway where glutathione peroxidase 4 (GPX4) and glutathione synthetase (GSS) were significant interacting proteins. Molecular docking and dynamic simulation studies confirmed the binding affinity and stability between CopA3 and CK with GSS and GPX4 proteins, suggesting the role of GNP-CK-CopA3 in ferroptosis induction. Overall, our study showed GNP-CK-CopA3 could play a dual role by inducing apoptosis and ferroptosis to induce AGS cell death.

Green synthesis of gold nanoparticles using Pelargonium Graveolens leaf extract: characterization and anti-microbial properties (An in-vitro study).

In recent years, there has been a notable increase in the level of attention devoted to exploring capabilities of nanoparticles, specifically gold nanoparticles AuNPs, within context of modern times. AuNPs possess distinct biophysical properties, as a novel avenue as an antibacterial agent targeting Streptococcus Mutans and Candida Albicans. The aim of this study to create a nano-platform that has the potential to be environmentally sustainable, in addition to exhibiting exceptional antimicrobial properties against Streptococcus Mutans as well as Candida Albicans. this study involved utilization of Pelargonium Graveolens leaves extract as a cost effective and environmentally sustainable approach for the green synthesis of AuNPs. Subsequently, physicochemical characteristics were assessed employing a variety of analytical methods, including as transmission electron microscopy, X-ray diffraction, Field Emission Scanning Electron Microscope, Zeta potential, Ultraviolet visible absorption spectroscopy, and Energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy. The antimicrobial efficacy against Streptococcus Mutans and Candida Albicans was evaluated. Nanoparticles of various shapes, including hexagonal, spherical, semi-spherical, and triangular, were synthesized. These nanoparticles exhibited a mean particle size of 294nm and demonstrated low degree of aggregation. These nanoparticles exhibited long-term stability and were capable of facilely combining with diverse bioactive compounds. The study demonstrated that AuNPs which is synthesized by green methods display potent antimicrobial properties. Utilization of Pelargonium Graveolens AuNPs may exhibit a promising potential as an antibacterial agent against Streptococcus Mutans and Candida Albicans. Nanoparticles (NPs) have the potential to serve as a novel approach for addressing pathogen infections as well as for biomedical, dental and pharmaceutical purposes in the future.

Investigation of different deposition methods for synthesized gold nanoparticles on a South African sugarcane leaves derived silica xerogel support

Value added materials made from agricultural residues are very attractive since they contribute in reducing environmental waste and enhancing economic sustainability. Two deposition methods were investigated where silica xerogel from sugarcane leaves (a waste from sugarcane industry) was used as a support for the synthesized gold nanoparticles. Biogenic silica was refluxed with sodium hydroxide at 80 °C to form sodium silicate solution. The gold nanoparticles were either synthesized in the sodium silicate solution or separately to form silica/Au nanoparticles through a sol-gel method. Ultraviolet (UV)-visible spectroscopy, x-ray powder diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), x-ray fluorescence spectroscopy (XRF), energy dispersive x-ray (EDX) and nitrogen adsorption-desorption were used to characterize the produced Si/Au nanoparticles. The two investigated methods resulted in distinctive deposition of gold nanoparticles on a silica xerogel support and also significantly different textural properties. The produced silica/gold nanoparticles had a Brunauer-Emmett-Teller (BET) surface area of up to 619 m2/g, pore diameter of 8.3 nm and pore volume of 1.28 cm3.g−1.

Assessing the Potential of Aconitum Laeve Extract for Biogenic Silver and Gold Nanoparticle Synthesis and Their Biological and Catalytic Applications.

The adoption of green chemistry protocols in nanoparticle (NP) synthesis has exhibited substantial potential and is presently a central focus in research for generating versatile NPs applicable across a broad spectrum of applications. In this scientific contribution, we, for the first time, examined the ability of Aconitum Laeve (A. Laeve) crude extract to synthesize silver and gold nanoparticles (AgNPs@AL; AuNP@AL) and explored their potential applications in biological activities and the catalytic degradation of environmental pollutants. The synthesized NPs exhibited a distinctive surface plasmon resonance pattern, a spherical morphology with approximate sizes of 5-10 nm (TEM imaging), a crystalline architecture (XRD analysis), and potential functional groups identified by FTIR spectroscopy. The antibacterial activity was demonstrated by inhibition zones that measured 16 and 14 mm for the AgNPs@AL and AuNP@AL at a concentration of 80 µg/mL against Staphylococcus aureus and 14 and 12 mm against Escherichia coli, respectively. The antioxidant potential of the synthesized NPs was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2-Phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-Oxide (PTIO), and 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assays. Our findings suggest that the AuNP@AL effectively countered the tested radicals considerably, displaying IC50 values of 115.9, 103.54, and 180.85 µg/mL against DPPH, PTIO, and ABTS, respectively. In contrast, the AgNPs@AL showed IC50 values of 144.9, 116.36, and 95.39 µg/mL against the respective radicals. In addition, both the NPs presented significant effectiveness in the photocatalytic degradation of methylene blue and rhodamine B. The overall observations indicate that A. Laeve possesses a robust capability to synthesize spherical nanoparticles, exhibiting excellent dispersion and showcasing potential applications in both biological activities and environmental remediation.

Epigallocatechin-3-gallate-synthesized gold nanoparticles modulate reactive oxygen species and antioxidant parameters in brain and heart tissues using a chicken embryo model

Chemically synthesized gold nanoparticles (AuNPs) come with drawbacks, such as biological toxicity and ecological imbalances. Nonetheless, a knowledge gap remains regarding their impact on oxidative and antioxidant parameters. Here, environmentally friendly AuNPs were synthesized using epigallocatechin-3-gallate (AuNPs-EGCG). The successful synthesis of AuNPs-EGCG were confirmed using ultraviolet–visible spectroscopy, Fourier-transform infrared spectroscopy, atomic force microscopy, and dynamic light scattering. Antioxidant activity was assessed using free radical 2,2-diphenyl-1-picrylhydrazyl, oxygen radical absorbance capacity, and ferric reducing antioxidant power assays, while cytotoxicity properties were evaluated in the NIH3T3 fibroblast cells. Furthermore, the impact of AuNPs-EGCG on oxidative stress was investigated in the hearts and brains of chicken embryos. AuNPs-EGCG exhibited no cytotoxicity and was not toxic for chicken embryos at higher concentrations. However, exposure to lower concentrations (100 and 30 μg/mL) caused an increase in reactive oxygen species (ROS) levels and a decrease in total antioxidant capacity in the heart and brain, resulting in a disturbance in the redox balance attributed to a reduction in catalase activity and glutathione (GSH) content, and an increase in glutathione peroxidase activity. In contrast, AuNPs-EGCG at 300 μg/mL promoted an increase in GSH levels and modulation of ROS, while also reducing vascular density in the chorioallantoic membrane. Furthermore, AuNPs-EGCG did not cause lipid or protein oxidation. The present study offers evidence that supports the investigation of how AuNPs-EGCG can modulate antioxidant defense mechanisms and assess the safety of phytoantioxidant-functionalized nanoparticles in vivo. This may lead to new and innovative strategies for the utilization of nanomaterials in biological systems.