Synthesis Of Metal Nanoparticles Research Articles

Green synthesis of copper nanoparticles by using pineapple peel waste: in vitro characterizations and antibacterial potential.

A considerable amount of fruit waste is being produced every day worldwide. The green synthesis of metal nanoparticles from fruit peel waste can be an innovative, cost-effective, and eco-friendly alternative to traditional methods. Copper nanoparticles (CuNPs) were synthesized by a green method using the pineapple peels extract (PLX) and copper sulfate pentahydrate. The formation of CuNPs was visually identified and detected by UV-Visible spectroscopy. The CuNPs were characterized by Fourier-transform infrared (FTIR) spectroscopy, particle size analyzer, scanning electron microscopy (SEM), and X-ray diffraction (XRD). The antioxidant and reducing power of CuNPs were conducted by %DPPH scavenging and electron transfer-based ferric reducing antioxidant power (FRAP) assay, respectively. The antibacterial properties of CuNPs were determined in gram-positive, and gram-negative bacteria. The results showed that the CuNPs were spherical in shape with mean particle size 290.5nm. The zeta potential of the nanoparticles was found to be -12.3mV indicating the instability in the colloidal state. The FTIR study confirmed the peaks of phytochemicals present in the PLX and the nanoparticles supporting the use of pineapple peels as stabilizing, reducing and capping agents. Both the DPPH and reducing power assay depicted that the synthesized CuNPs had significant antioxidant activity. However, the synthesized CuNPs had strong inhibitory capacity against both gram-positive and gram-negative test organisms. Thus, the CuNPS could be used for its viable antibacterial potential to preserve fruits, flowers, and vegetables from bacterial contamination.

Cytotoxic activity of bimetallic Ag@Se green synthesized nanoparticles using Jerusalem Thorn (Parkinsonia aculeata).

Introduction: The process of green synthesis of metal nanoparticles is considered to be eco-friendly and cost-effective. Methods: In this study, bimetallic Ag@Se-P and Ag@Se-S nanoparticles were synthesized successfully using Parkinsonia aculeata aerial parts and seed extracts. The phytochemical contents in P. aculeata aerial parts and seed aqueous extract serve as reducing and stabilizing capping agents without the need for any chemical stabilization additive in the synthesis of bimetallic nanoparticles. Result and Discussion: The obtained results from UV-vis spectrophotometry, scanning electron microscopy (SEM), X-ray powder diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and Fourier-transform infrared spectroscopy (FT-IR) confirmed the successful synthesis of bimetallic nanoparticles with cluster irregular spherical morphology, crystalline nature, and average particle sizes of 17.65 and 24.36nm for Ag@Se-S and Ag@Se-P, respectively. The cytotoxicity assessment of greenly synthesized nanomaterials using seed and plant extracts showed cell inhibition >50μg/mL. Ag@Se-S and Ag@Se-P seed and plant extracts significantly reduced LPS-induced inflammation, which was assessed by NO and cytokines IL-1β, IL-6, and TNF-α. The mRNA and protein expression levels of phosphoinositide 3 kinase (PI3K) and nuclear factor kappa B (NFkB) were significantly overexpressed in LPS-induced RAW 264.7 cell lines. Ag@Se-S and Ag@Se-P downregulated the expression of PI3K and NFkB in LPS-induced cell models.

Highly efficient catalytic degradation of organic dyes using iron nanoparticles synthesized with Vernonia Amygdalina leaf extract

Today, nanoscience explores the potential of nanoparticles due to their extraordinary properties compared to bulk materials. The synthesis of metal nanoparticles using plant extracts is a very promising method for environmental remediation, which gets global attention due to pollution-led global warming. In the present study, iron nanoparticles (FeNPs) were successfully synthesized by the green method using Vernonia amygdalina plant leaf extract as a natural reducing and capping agent. Biosynthesized FeNPs were characterized with different analytical techniques such as UV–visible, FT-IR, XRD, and SEM. The analysis revealed the formation of amorphous FeNPs with an irregular morphology and non-uniform distribution in size and shape. The average particle size was approximately 2.31 µm. According to the catalytic degradation investigation, the FeNPs produced via the green approach are highly effective in breaking down both CV and MB into non-toxic products, with a maximum degradation efficiency of 97.47% and 94.22%, respectively, when the right conditions are met. The kinetics study exhibited a high correlation coefficient close to unity (0.999) and (0.995) for the degradation of MB and CV, respectively, for the zero-order pseudo-kinetics model, which describes the model as highly suitable for the degradation of both dyes by FeNPs compared to other models. The reusability and stability of biosynthesized nano-catalysts were studied and successfully used as efficient catalysts with a slight decrease in the degradation rate more than four times. The results from this study illustrate that green synthesized FeNPs offer a cost-effective, environmentally friendly, and efficient means for the catalytic degradation of organic dyes.

Biosynthesis of Cu-In-S Nanoparticles by a Yeast Isolated from Union Glacier, Antarctica: A Platform for Enhanced Quantum Dot-Sensitized Solar Cells.

In recent years, the utilization of extremophile microorganisms for the synthesis of metal nanoparticles, featuring enhanced properties and diverse compositions, has emerged as a sustainable strategy to generate high-quality nanomaterials with unique characteristics. Our study focuses on the biosynthesis of Cu-In-S (CIS) nanoparticles, which has garnered considerable attention in the past decade due to their low toxicity and versatile applications in biomedicine and solar cells. Despite this interest, there is a notable absence of reports on biological methods for CIS nanoparticle synthesis. In this research, three yeast species were isolated from soil samples in an extreme Antarctic environment-Union Glacier, Ellsworth Mountains. Among these isolates, Filobasidium stepposum demonstrated the capability to biosynthesize CIS nanoparticles when exposed to copper sulfate, indium chloride, glutathione, and cysteine. Subsequent purification and spectroscopic characterization confirmed the presence of characteristic absorbance and fluorescence peaks for CIS nanoparticles at 500 and 650 nm, respectively. Transmission electron microscopy analysis revealed the synthesis of monodisperse nanoparticles with a size range of 3-5 nm. Energy dispersive X-ray spectroscopy confirmed the composition of the nanoparticles, revealing the presence of copper, indium, and sulfur. The copper/indium ratio ranged from 0.15 to 0.27, depending on the reaction time. The biosynthesized CIS nanoparticles showed higher photostability than biomimetic nanoparticles and demonstrated successful application as photosensitizers in quantum dot-sensitized solar cells (QDSSC), achieving a conversion efficiency of up to 0.0247%. In summary, this work presents a cost-effective, straightforward, and environmentally friendly method for CIS nanoparticle synthesis. Furthermore, it constitutes the first documented instance of a biological procedure for producing these nanoparticles, opening avenues for the development of environmentally sustainable solar cells.

Utilization of Azadirachta Indica Latex for Synthesis of Silver Nanoparticles its Application in Photocatalytic Degradation of Methylene Blue Dye

The use of extract from indigenous plant species for the synthesis of metallic nanoparticles has significant importance as they have a capacity to act as potential reducing, capping and stabilizing agent. In this research, latex of Azadirachta indica (Neem) was selected for green synthesis of silver nanoparticles (AgNPs). Maximum absorbance was achieved at 425 nm (λmax) for AgNPs. FTIR vibrational peaks of AgNPs were observed at 3462, 2933, 1732, 1658, 1458, 1381, 1244, and 1028 and near 600 cm -1. Moreover, Atomic Force Microscopy (AFM) showed that the synthesized AgNPs were face-centered cuboid, spherical, hexahedral, and pentagonal structures ranging in size between 7.15-71.5nm. XRD analysis shows that most of the nanoparticles have spherical crystalline structure. Photocatalytic degradation of hazardous azo dye; Methylene blue dye (MB) was performed in the presence of synthesized AgNPs as catalysts under UV-induced photocatalytic degradation. The degradation efficiency after 180 minutes of reaction time was 82 % which proposes its potential to use as environmental pollutant eradicators in the treatment of textile industries wastewater.

Green-route synthesis of ZnO nanoparticles via Solanum surattense leaf extract: Characterization, biomedical applications and their ecotoxicity assessment of zebrafish embryo model

Biogenic synthesis (green synthesis) of metal or metal oxide nanoparticles has recently become important to researchers due to its improved antibacterial properties and associated applications. The present investigation has been carried out to produce zinc oxide nanoparticles (ZnO NPs) using a leaf aqueous extract of Solanum surattense as a reducing and stabilizing agent. The synthesized NPs have been studied using UV–visible, FT-IR, XRD, SEM-TEM, and EDX analysis. The highest UV peak produced by the synthesized ZnO NPs was 294 nm. The resulting ZnO NPs were crystalline, confirmed by XRD measurements. FT-IR demonstrates the presence of OH stretching and CC bending, functional groups of the plant extract stabilizing activity on the NP's outer layer. SEM & TEM investigation confirmed that the NPs were spherical, and their diameters were 25.14 ± 7.4 nm. At a 100 μg/mL concentration, the NPs showed significant antibiofilm activity against Streptococcus mutans and Enterococcus faecalis. Furthermore, the ZnO NPs had remarkable antibacterial activity against two targeted bacteria. In ABTS and DPPH scavenging tests, ZnO NP's antioxidant functions significantly surpassed the ascorbic acid standard. The ZnO NPs significantly inhibited the MDA-MB-231 human breast cancer cell line in vitro, and their IC50 value was 40 μg/mL. The pkCSM server and ADMETlab2 online services analyzed the pharmacokinetics characteristics. Tetratriacontane and streptomycin binding energies have been identified to be -8.7 and -7.6 kcal/mol, respectively. Lastly, the appearance of shorter bodies was observed only at doses above 5 mg/mL in the toxicity test done on zebrafish eggs. The work shows that phyto-synthesized ZnO NPs employing S. surattense extract may be an alternative biological agent in the future.

Green biologically synthesized metal nanoparticles: biological applications, optimizations and future prospects.

In green biological synthesis, metal nanoparticles are produced by plants or microorganisms. Since it is ecologically friendly, economically viable and sustainable, this method is preferable to other traditional ones. For their continuous groundbreaking advancements and myriad physiochemical and biological benefits, nanotechnologies have influenced various aspects of scientific fields. Metal nanoparticles (MNPs) are the field anchor for their outstanding optical, electricaland chemical capabilities that outperform their regular-sized counterparts. This review discusses the most current biosynthesized metal nanoparticles synthesized by various organisms and their biological applications along with the key elements involved in MNP green synthesis. The review is displayed in a manner that will impart assertiveness, help the researchers to open questions, and highlight many points for conducting future research.

Comparative Bioactivity Analysis of Green-Synthesized Metal (Cobalt, Copper, and Selenium) Nanoparticles.

Aim This study involves synthesizing metal nanoparticles (NPs) via the green synthesis method using Millettia pinnata leaf, Acacia auriculiformis bark, and Citrus sinensis peel and comparatively evaluating their antibacterial activity in vitro through the analysis of cobalt oxide NPs (CoNPs), copper NPs (CuNPs), and selenium NPs (SeNPs). This research contributes to eco-friendly approaches for producing functional nanomaterials with potential applications in medicine and environmental remediation. Materials and methods The metal NPs were synthesized using M. pinnata leaf, A. auriculiformis bark, and C. sinensis peel. These leaf extracts act as self-reducing and stabilizing agents. The antibacterial activity was assessed by the well diffusion method. Cultures of pathogenic bacteria species such as Staphylococcus aureus, Escherichia coli, Bacillus subtilis, and Pseudomonas aeruginosa were prepared. NPs were applied to the culture, and zones of inhibition (ZOIs) were measured. The data were statistically analyzed to compare the antibacterial efficacy of the different NPs. Results The successfully synthesized CoNPs, CuNPs, and SeNPs showed distinctive phytochemical properties. CoNPs exhibited the highest ZOI against most bacterial strains, with CuNPs and SeNPs following. CoNPs consistently showed superior performance compared to CuNPs and SeNPs. Conclusion Our study analyzed the bioactivity of metal NPs produced using green synthesis with plant extracts. CoNPs have shown superior antibacterial effectiveness against both Gram-positive and Gram-negative bacteria when compared to CuNPs and SeNPs. This may be due to their larger surface area, smaller size, unique electrical, magnetic, and catalytic properties, as well as their improved contact with the bacterial cell wall and membrane.

Bespoke Metal Nanoparticle Synthesis at Room Temperature and Discovery of Chemical Knowledge on Nanoparticle Growth via Autonomous Experimentations

AbstractThe optimization of nanomaterial synthesis using numerous synthetic variables is considered to be an extremely laborious task because conventional combinatorial explorations are prohibitively expensive. In this work, an autonomous experimentation platform developed for the bespoke design of metal nanoparticles (NPs) with targeted optical properties is reported. This platform operates in a closed‐loop manner between the batch synthesis module of metal NPs and the UV–vis spectroscopy module, based on the feedback of the AI optimization modeling. With silver (Ag) NPs as a representative example, it is demonstrated that the Bayesian optimizer implemented with the early stopping criterion can efficiently produce Ag NPs at room temperature precisely possessing the desired absorption spectra within only 200 iterations (when optimizing among five aqueous synthetic reagents). In addition to the outstanding material developmental efficiency, the analysis of synthetic variables further reveals a novel chemistry involving the quantitative effects of citrate in Ag NP synthesis. The amount of citrate is key to controlling the competition between spherical and plate‐shaped NPs and, as a result, affects the shapes of the absorption spectra as well. This study highlights both capabilities of the platform to enhance search efficiencies and to provide novel chemical knowledge by analyzing datasets accumulated from autonomous experimentations.

Green synthesis of silver nanoparticles using Illicium verum extract: Optimization and characterization for biomedical applications

Abstract The synthesis of noble metal nanoparticles is currently experiencing substantial development and considerable attention. Plant extracts are commonly used for the biological synthesis of nanoparticles because they contain biologically active constituents. In our present study, silver nanoparticles (AgNPs) were synthesized using an aqueous Illicium verum (Star anise) extract to evaluate their antimicrobial, antioxidant, and cytotoxicity activities. For maximum yields of AgNPs, the extract (2.5 ml), silver ions (500 µM), and pH (8) were shown to be the ideal nanoparticle production parameters. The visual colour shifted from pale brown to dark brown when the ultraviolet-visible spectrophotometer was used to validate the synthesis of AgNPs. A transmission electron microscope was utilized to evaluate nanoparticles’ physical nature. The presence of silver metal with face-centred cubic symmetry was confirmed by X-ray diffraction analysis. Fourier-transform infrared spectroscopy was used to identify the functional groups in charge of reducing silver ions (Ag+) and the stability of AgNPs produced using the I. verum aqueous extract. The agar well diffusion method investigated the antibacterial activity of I. verum silver nanoparticles (Iv-AgNPs) against pathogenic bacteria and fungi. At higher doses (100 µg·mL−1), the highest zone of inhibition was observed, and spherical AgNPs demonstrated the antibacterial activity. The I. verum extract and Iv-AgNPs enhanced (70%) their free radical scavenging activity at 500 µg·mL−1 according to the 2,2-diphenyl-1-picrylhydrazyl assay. Moreover, the cytotoxicity of Iv-AgNPs against the HCT-116 human colon cancer cell line indicated cell inhibition in a dose-dependent manner. Ultimately, the findings of this study indicate that techniques used to produce AgNPs are environmental friendly, cost-effective, harmless, uncomplicated, and can effectively tackle a broad spectrum of medical and nutritional concerns.

جسيمات النحاس النانوية المركبة في مصفوفة البوليمر الحيوي وتطبيقاتها في النشاط المضاد للبكتيريا

النحاس هو بديل أرخص من العديد من المعادن النبيلة مع مجموعة من التطبيقات المحتملة في مجال علم النانو وتكنولوجيا النانو. ومع ذلك ، فإن جسيمات النحاس النانوية لها قيود كبيرة ، والتي تشمل الأكسدة السريعة عند التعرض للهواء. لذلك ، تم تطوير مسارات بديلة لتجميع الجسيمات النانوية المعدنية في وجود البوليمرات والمواد الخافضة للتوتر السطحي كمثبتات ، ولتشكيل الطلاءات على سطح الجسيمات النانوية. هذه المواد الخافضة للتوتر السطحي والروابط البوليمرية مصنوعة من بتروكيماويات غير متجددة. نظرًا لمحدودية الموارد الأحفورية ، فإن إيجاد بديل متجدد وقابل للتحلل البيولوجي يعد أمرًا واعدًا ، حيث هدفت الدراسة إلى إعداد وتوصيف وتقييم الخصائص المضادة للبكتيريا لجسيمات النحاس النانوية. تم تحضير جسيمات النحاس النانوية باستخدام البوليمر الحيوي الجيلاتيني ، أيونات CuSO4.5H2O والهيدرازين كمثبت ، ملح سلائف وعامل اختزال على التوالي. ومع ذلك ، تم استخدام محلول فيتامين C و NaOH أيضًا كمضاد للأكسدة وضبط درجة الحموضة. تم تمييز جسيمات النحاس النانوية المركبة باستخدام التحليل الطيفي المرئي للأشعة فوق البنفسجية (UV-vis) ، التحليل الحراري الوزني (TGA) ، مسحوق قياسات زيتا المحتملة ، حيود الأشعة السينية (XRD) ، المجهر الإلكتروني لمسح الانبعاث الميداني والمجهر الإلكتروني النافذ (TEM). يؤكد طيف الامتصاص المرئي للأشعة فوق البنفسجية تكوين CuNPs ، والتي أظهرت أقصى امتصاص عند 583 نانومتر. أشارت النتائج التي تم الحصول عليها من TEM إلى انخفاض في حجم الجسيمات من التركيز المنخفض إلى التركيز العالي للمواد الداعمة. وجد أن التركيز الأمثل للجيلاتين هو 0.75٪ بالوزن. المواد الداعمة المستخدمة في هذا التركيب متوافقة حيوياً والمنتجات التي تم الحصول عليها مستقرة في الهواء. تُظهر CuNPs المُصنَّعة أنشطة واعدة مضادة للجراثيم ضد B. subtilis (B29) و S. aureus (S276) و S. choleraesuis (ATCC 10708) و E. coli (E266) كبكتيريا موجبة وسالبة الجرام على التوالي.

Green Synthesis of Metal Nanoparticles and their Medicinal Application in Treatment of Cancer

Study of nanoparticles has attracted the immense attention of researchers because of their wide applications in the medicine, chemical industries, and biotechnology. This paper highlights that plants and microbes can be a source of bio-compounds in nanoparticle synthesis in place of toxic chemicals. As this is an environmentally friendly approach following the principles of green synthesis which is cheap and is not toxic. Both sources provide antioxidant, anticancer, and antimicrobial properties which hold great importance in the manufacturing of NPs. This review aims to bring together the diversity of synthesized metallic nanoparticles mediated by plant extracts, fungi, algae, bacteria and yeasts. All the mentioned bio-resources contain biomolecule which includes protein and enzyme which serves the twin action of both reduction and capping of the synthesized nanoparticles. The synthesized NPs are characterized by using UV-visible spectrometry, FT-IR, XRD, TEM, SEM and EDX. Also, the biomedical application of the synthesized NPs is explored in the treatment of cancer.

The Biogenetic Synthesis of Metallic Nanoparticles and the Role they Play in the Anti-inflammatory Drug Treatment.

Nanoscience and nanotechnology have resulted in the continuous development of new nanomaterials with remarkable properties that make them appealing for pharmaceutical applications. The biocompatibility of metallic nanoparticles is of increasing interest for research scientists currently working towards developing novel nano-based medicines, industrial chemicals, and antigens. There is also a particular interest in using them to counter mutations that up-regulate inflammation enhancers to produce a range of inflammation-related pathologies. The following review discusses the anti-inflammatory mechanisms of metallic bioconjugated (silver, gold, zinc oxide, titanium dioxide, and selenium) nanoparticles. The current study focuses on nanoparticle manufacturing technologies and the inflammatory response. A thorough search was conducted in several databases, including Scopus, Embase, Cochrane, and PubMed. The search terms used included: Alzheimer's disease, mechanism of action, neuroinflammation, the reaction of Mast cells to stress and neuroinflammation. The study included all publications published in English. Green-synthesised nanoparticles can suppress the NF-B and cyclooxygenase-2 pathways, preventing the production of proinflammatory cytokines and ROS scavenging mechanisms. Metallic nanoparticles with anti-inflammatory properties, such as stability and specific targeting, have been briefly discussed. The current research focuses on metallic nanoparticles employed as anti-inflammatory medication molecules, although nanoparticles have applications in various areas (medicine, chemical engineering, and agriculture). Nanoparticles have a large surface-to-volume ratio, which can help them to penetrate cell membranes, and because of their solid ligand-binding capabilities, nanoparticles have been used in the medical treatment of inflammatory pathologies.

SYNTHESIS OF SILVER NANOPARTICLES FROM LANNEA ACIDA VIA AQUEOUS AND METHANOLIC LEAF EXTRACT

The reducing ability of plant extract cost-effectiveness is the major factor to consider in the green synthesis of metal nanoparticles. The present study investigates two different extraction methods for the green synthesis of silver nanoparticles (AgNPs) via aqueous and methanolic Lannea acida leaf extract for the first time. The effect of silver nitrate concentration, and quantity of the silver nitrate (volume) on that of plant extract and studied by UV–Vis spectroscopy and Fourier-transform infrared (FT-IR) spectroscopy. The methanolic extract silver nanoparticles show a remarkable difference compared to silver nanoparticles synthesized from the aqueous extract, this is ascertained that methanol has the potential applications than the silver nanoparticles synthesized from aqueous extract.

Eco-friendly Synthesis of Azadirachta indica-based Metallic Nanoparticles for Biomedical Application & Future Prospective.

The process of producing the metallic nanoparticles (MNPs) in a sustainable and environment- friendly process is very desirable due to environmental hazards posed by climatic changes. Biomedical one of the fields classified under nanoscience, nanoparticles have a potential synthetic application, which makes it a vast area of research. These particles can be prepared using chemical, physical, and biological methods. One of the methods of synthesis of nanoparticles is by the use of plant extracts, known as green synthesis. Because of its low cost and nontoxicity, it has gained attention in recent times. This review was conducted to find the possible outcomes and uses of metallic nanoparticles synthesized using different parts like gum, root, stem, leaf, fruits, etc. of Azadirachta indica (AI). AI, a popular medicinal plant commonly known as neem, has been studied for the green synthesis of NPs by using the capping and reducing agents secreted by the plant. Various phytochemicals identified in neem are capable of metal ion reduction. Green synthesis of NPs from neem is an eco-friendly and low-cost method. These NPs are reported to exhibit good antimicrobial activity. The review covers the preparation, characterization, and mechanism associated with the antibacterial, anticancer, and neurological diseases of the MNPs. Furthermore, the limitations associated with the existing NPs and the prospects of these NPs are also examined.

Biogenic Synthesis and Characterisation of Flueggea leucopyrus Willd Leaf Mediated Copper Nanoparticles for Antibacterial, Antioxidant, and Antidiabetic Activities

IntroductionThe chemical synthesis of metal Nanoparticles could be changed into green synthesis if solvents, stabilising agents, and reducing agents are environmentally friendly. Our aims were to synthesise and characterise bioconjugated copper nanoparticles (CuNPs) and evaluate their antibacterial, antioxidant, and antidiabetic activities. MethodsThis study was made to synthesise CuNPs using Flueggea leucopyrus Willd leaf extract. The produced CuNPs were characterised using UV-visible, Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), TEM, EDX, and Zeta-potential analytical methods. The antibacterial, antioxidant, and antidiabetic properties of CuNPs were screened through disc diffusion methods, 2,2-diphenyl-1-picrylhydrazyl radical quenching, and alpha-amylase inhibition assay, respectively. ResultsThe CuNPs are poly-dispersed, spherical, crystalline, and stable with an average particle size of 20 nm. These nanoparticles show antibacterial activity and exhibit the same inhibition zone against S aureus and P aruginosa (13 mm), a strong zone for E faecalis, and no inhibition zone for E coli bacteria. The CuNPs demonstrated dose-dependent sequencing and inhibition activities with an IC50 value of 100.06 ppm and 435.68 ppm, respectively. ConclusionsThis study shows that these poly-disperse CuNPs could act as a bacterial resistance agent, antioxidant, and antidiabetic drug. It concluded that CuNPs made from medicinal plant leaf extract have good inhibitory potential against alpha-amylase, one of the main pharmacological targets for treating type 2 diabetes.

Superoxide Dismutase Catalyzed Size-Adjustable Selenium Nanoparticles in Saccharomyces boulardii.

Selenium nanoparticles (SeNPs) are important and safe food and feed additives that can be used for dietary supplementation. In this study, a mutagenic strain of Saccharomyces boulardii was employed to obtain biologically synthesized SeNPs (BioSeNPs) with the desired particle size by controlling the dosage and duration of sodium selenite addition, and the average particle size achieved was 55.8 nm with protease A encapsulation. Transcriptomic analysis revealed that increased expression of superoxide dismutase 1 (SOD1) in the mutant strain effectively promoted the synthesis of BioSeNPs and the formation of smaller nanoparticles. Under sodium selenite stress, the mutant strain exhibited significantly increased expression of glutathione peroxidase 2 (GPx2), which was significantly greater in the mutant strain than in the wild type, facilitating the synthesis of glutathione selenol and providing abundant substrates for the production of BioSeNPs. Furthermore, based on the experimental results and transcriptomic analysis of relevant genes such as sod1, gpx2, the thioredoxin reductase 1 gene (trr1) and the thioredoxin reductase 2 gene (trr2), a yeast model for the size-controlled synthesis of BioSeNPs was constructed. This study provides an important theoretical and practical foundation for the green synthesis of controllable-sized BioSeNPs or other metal nanoparticles with potential applications in the fields of food, feed, and biomedicine.

Kinetically Controlled Synthesis of Metallic Glass Nanoparticles with Expanded Composition Space.

Nanoscale metallic glasses offer opportunities for investigating fundamental properties of amorphous solids and technological applications in biomedicine, microengineering, and catalysis. However, their top-down fabrication is limited by bulk counterpart availability, and bottom-up synthesis remains underexplored due to strict formation conditions. Here, a kinetically controlled flash carbothermic reaction is developed, featuring ultrafast heating (>105 K s-1) and cooling rates (>104 K s-1), for synthesizing metallic glass nanoparticles within milliseconds. Nine compositional permutations of noble metals, base metals, and metalloid (M1─M2─P, M1 = Pt/Pd, M2 = Cu/Ni/Fe/Co/Sn) are synthesized with widely tunable particle sizes and substrates. Through combinatorial development, a substantially expanded composition space for nanoscale metallic glass is discovered compared to bulk counterpart, revealing that the nanosize effect enhances glass forming ability. Leveraging this, several nanoscale metallic glasses are synthesized with composition that have never, to the knowledge, been synthesized in bulk. The metallic glass nanoparticles exhibit high activity in heterogeneous catalysis, outperforming crystalline metal alloy nanoparticles.

Sustainable Finished Leather Preservation

Part 1 of the current paper described the green synthesis of myrobalan capped copper nanoparticles for the preservation of the finished leather. In Part II of the current study, Copper Nanoparticles (CuNPs) were synthesized using green synthesis with wattle (tannin) extract as a reducing agent. Green synthesis is the preferred approach for the synthesis of metal nanoparticles due to its eco-friendly and cost-effectiveness for the preservation of finished leather. To improve the antibacterial qualities of leather with different types of finishes, the resin finished leather was coated with synthesized wattle copper nanoparticles (W-CuNPs). The chemical constituents of wattle induce the reduction of Cu2+ ions to CuNPs with the capping process and also remain as a stabilizing agent for the capping process. The formation of W-CuNPs was confirmed by UV-Spectroscopy at an absorbance of 467 nm. The identified functional groups such as -OH, C=C, and C-N were analyzed by Fourier transform infrared spectrum (FT-IR) which are responsible for the reduction and stabilization of copper nanoparticles. The spherical shape of the nanoparticles was ascertained by Scanning Electron Microscope (SEM), whereas Energy dispersive X-ray (EDX) studies confirmed the presence of copper with 65%. The average particle size of W-CuNPs was found to be 96 nm. The zeta potential value of -24 mv affirmed the stability of the W-CuNPs. The maximum zone of inhibition was 12 mm against Gram-positive (Bacillus subtilis) and 11 mm against Gram-negative (Serratia marcescens) bacteria on W-CuNPs coated finished leather, which exhibits strong antimicrobial activity. Hence, CuNPs synthesized by wattle extract have the potential to preserve the finished leather and its products as an antibacterial agent.

Surface structuring and in situ synthesis of nanoparticles by ultrashort laser processing on hydroxyapatite

Ultrashort laser pulses represent a versatile tool that finds application in a variety of fields allowing precise and controlled modification of any kind of materials. The material surface modification, by inducing the formation of micro and nanostructures or providing chemical changes, or its functionalization with other materials, in form of nanoparticles, strongly affects the behavior and performances of such materials. The surface structuring and the synthesis and deposition of metallic nanoparticles has both been obtained by laser exposure. The two processes are performed consecutively, on hydroxyapatite sample surface. The synthesis of silver nanoparticles (AgNPs) takes place on the sample surface, while immersed in a solution of silver nitrate (AgNO3), by laser-induced multiphoton photoreduction of silver ions (Ag+).