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Lameness is a crucial problem in dairy farming. It worsens the welfare of cattle, reduces the milk yield, and causes economic losses. The etiology of lameness is varied and the cattle's condition may be infectious or non-infectious. The aim of this research was to analyze the biocidal properties of silver (AgNPs), gold (AuNPs), and copper (CuNPs) nanoparticles against bacteria causing lameness in cattle. The isolated pathogens used were Aerococcus viridans, Corynebacterium freneyi, Corynebacterium xerosis, and Trueperella pyogenes. The tested concentrations of nanoparticles were 50, 25, 12.5, 6.25, 3.125, and 1.56 mg/L. The methods used included the isolation of pathogens using standard microbiological procedures and their identification using mass spectrometry, physicochemical analysis, transmission electron microscopy, and cytotoxicity tests. Studies have shown that AgNPs at 3.125 and 1.56 mg/L concentrations, and CuNPs at 25 and 12.5 mg/L concentrations, have strong biocidal properties, while AuNPs have the weakest antimicrobial properties. The very limited number of in vivo studies focusing on lameness prevention in cattle indicate that new solutions need to be developed. However, further studies are necessary to evaluate if nanoparticles (NPs) may, in the future, become components of innovative biocides used to prevent lameness in dairy cattle. [ABSTRACT FROM AUTHOR]

Particle plasmon resonance (PPR), or localized surface plasmon resonance (LSPR), utilizes intrinsic resonance in metal nanoparticles for sensor fabrication. While diffraction grating waveguides monitor bioaffinity adsorption with out-of-plane illumination, integrating them with PPR for biomolecular detection schemes remains underexplored. This study introduces a label-free biosensing platform integrating PPR with a diffraction grating waveguide. Gold nanoparticles are immobilized on a glass slide in contact with a sample, while a UV-assisted embossed diffraction grating is positioned opposite. The setup utilizes diffraction in reflection to detect changes in the environment's refractive index, indicating biomolecular binding at the gold nanoparticle surface. The positional shift of the diffracted beam, measured with varying refractive indices of sucrose solutions, shows a sensitivity of 0.97 mm/RIU at 8 cm from a position-sensitive detector, highlighting enhanced sensitivity due to PPR–diffraction coupling near the gold nanoparticle surface. Furthermore, the sensor achieved a resolution of 3.1 × 10−4 refractive index unit and a detection limit of 4.4 pM for detection of anti-DNP. The sensitivity of the diffracted spot was confirmed using finite element method (FEM) simulations in COMSOL Multiphysics. This study presents a significant advancement in biosensing technology, offering practical solutions for sensitive, rapid, and label-free biomolecule detection. [ABSTRACT FROM AUTHOR]

Iodide has long been recognized as an effective shape-directing agent for facilitating the growth of anisotropic noble metal nanostructures. However, little attention has been paid to the specific interaction between iodide and metal nanoparticles. In this study, we demonstrate the selective recognition of iodide in solution by the carbon-dot-gold nanoparticles (Cdot-AuNPs) ensemble. Irregularly-shaped AuNPs were generated through the reduction of HAuCl4 by citrate ions and stabilized by Cdot at ambient temperature. Upon the addition of iodide, the color of the solution changed from blue to red with the growth of AuNPs to semi-spherical nanoparticles, as confirmed by transmission electron microscopy. The selectivity test validated that only iodide could induce this specific visual response, highlighting a novel interaction mechanism between iodide and AuNPs. The recognition of iodide by this Cdot-AuNPs ensemble showed good resistance toward many environmentally relevant metal ions, particularly Ca2+, providing potential for the identification of iodide ions in real samples. Mixing tetrachloroauric acid, sodium citrate, and bee pollen-derived carbon dots (Cdot) at ambient temperature leads to the preparation of Cdot-AuNPs ensemble for the specific colorimetric recognition of iodide by reshaping the dimensions of the AuNPs. [ABSTRACT FROM AUTHOR]

Plasmonic nanoparticles play a pivotal role in various research areas due to their exceptional optical and thermo‐optical properties, like high spectral tunability and efficient light‐to‐heat conversion. Gold, with its biocompatibility, low cytotoxicity, and tunable resonances , makes gold nanoparticles ideal for photothermal therapies. Geometries, including spheres, core–shells, rods, disks, stars, nanocages, and nanotoroids, are extensively studied, with the gold nanodoughnut emerging as one of the most promising ones due to its ability to produce high temperatures and rotational stability. Nevertheless, the fabrication of metallic toroidal shapes remains a challenge. Recent advances in DNA‐based nanotechnology, especially DNA‐origami techniques, provide feasible route for the fabrication of this geometry through metallization reactions or attachment of metal nanoparticles. However, particles manufactured using this method possess a DNA core that influences their thermoplasmonic performance. In this work, a theoretical investigation is conducted on the thermoplasmonic response of DNA‐origami‐based core/shell toroids (CSTs) for photothermal applications. Key parameters that optimize the CST thermoplasmonic response are identified, and compared with their solid counterparts and discrete metallic coatings. Additionally, the CSTs tolerance to random rotations is assessed, providing insights into their behavior in fluidic environments and implications for its practical consideration. [ABSTRACT FROM AUTHOR]

MOFs are known for their absorption properties and widely used for accumulation, filtering, sensorics, photothermal, catalytical and other applications. Their combination with plasmonic metal nanoparticles leads to hybrid structures that profit from the stabilizing effect and high porosity of the MOF as well as the optical and electronic properties of the nanoparticles. The growth of MOFs on plasmonic nanoparticles can be monitored in‐situ using LSPR spectroscopy, simultaneously applying microfluidic reaction conditions for the fabrication of NP@MOF structures. Here, a systematic study is conducted using LSPR spectroscopy for the monitoring of the Layer‐by‐Layer deposition of twelve different MOFs, determining the suitability of LSPR spectroscopy for this purpose. In addition to some well‐investigated materials like HKUST‐1, other MOFs such as MIL‐53, MIL‐88 A and Cu‐BDC are deposited successfully. For some MOFs such as Zn‐Fum, the LSPR experiment indicates that no deposition had taken place. The results are confirmed with AFM, SEM and XPS measurements. This work shows that LSPR spectroscopy is suitable for the in‐situ monitoring of LbL MOF growth and the microfluidic setup is a very promising method for the controlled manufacturing of NP@MOF hybrid structures. Further studies may include the optimization of the synthesis process or the transfer to other materials. [ABSTRACT FROM AUTHOR]

In(III) tetraarylporphyrin complexes with 4‐thiomethylphenyl (1‐InPor), thien‐3‐yl (2‐InPor), thien‐2‐yl (3‐InPor) and 5‐bromothien‐2‐yl (4‐InPor) meso‐aryl rings have been synthesized and characterized. The complexes have been conjugated to gold and silver nanoparticles (AuNPs and AgNPs). The photodynamic antimicrobial chemotherapy (PACT) activities of 1–4‐InPor and their AuNP and AgNP conjugates have been investigated against both planktonic bacteria and biofilms of Gram‐(+) S. aureus and Gram‐(−) E. coli. 2.5 μg.mL−1 solutions of 1–4‐InPor exhibited favorable PACT activities against planktonic S. aureus with high Log10 reduction values in the 4.28–7.69 range upon 75 min photoirradiation with a Thorlabs M625L3 LED (240 mW.cm−2) mounted onto the illumination chamber of a Modulight 7710 medical laser system to provide a dose at the well‐plate of 86 mJ.cm−2.min−1. In contrast, low values in the 1.4–1.9 range were obtained against E. coli with 10 μg.mL−1 solutions. 1–4‐InPor exhibited relatively low PACT activity against the biofilm cells of S. aureus and E. coli. Conjugation of 1–4‐InPor to AgNPs and AuNPs significantly enhanced the PACT activities. This is demonstrated by the complete eradication of planktonic S. aureus at shorter irradiation times with high Log10 values>7.69 and moderate Log10 values>2 against planktonic E. coli for the meso‐thienylporphyrin conjugates. [ABSTRACT FROM AUTHOR]

The limitations of conventional template‐based methods for the deposition of nanoparticle assemblies into defined patterns on solid substrates call for the development of techniques that do not require templates or lithographic masks. The use of optically‐induced thermal gradients to drive the migration of colloids toward or away from a laser spot, known as opto‐thermophoresis, has shown promise for the low‐power trapping and optical manipulation of a variety of colloidal species. However, the printing of colloids using this technique has so far not been established. Herein, a method for the optically directed printing of noble metal nanoparticles, specifically gold nanospheres is reported. The thermophoresis of the polymer polyvinylpyrrolidone and gold nanospheres toward a laser spot led to the deposition of nanoparticle aggregates, capable of serving as surface‐enhanced Raman scattering substrates. The influence of heating laser power and the concentrations of polymer, salt, and surfactant on the nanoparticle deposition rate and structure of the printed pattern are studied, showing that a variety of conditions can permit printing, suggesting facile generalization to different nanoparticle compositions, sizes, and shapes. These findings will greatly benefit future efforts for directed nanoparticle assembly, and drive applications in sensing, photothermal heating, and relevant applications in biomedicine and devices. [ABSTRACT FROM AUTHOR]

Interfacial solar steam generation is a potential technology to relieve the freshwater shortage. However, developing a cost-effective method to design photo-absorbers with steady desalination performance remains a significant challenge. In this study, we designed, the Polyvinyl Alcohol (PVA): Glutaraldehyde (GA)/silver and gold plasmonic nanoparticle/activated carbon hydrogel nanocomposite as sponge-like photo-absorber materials. Glutaraldehyde (GA) as a simple chemical crosslinking added to PVA/AC hydrogel along with to Au or Ag nanoparticles for increasing the light absorption. The optical properties results show that by adding gold and silver nanoparticles as plasmonic agent in this hydrogel, the light absorption is increased in wet hydrogel which can reach 74% with water evaporate rate of 5.58 kg−2 m−2 h−1. The PVA: GA: Au hydrogel (AC) nanocomposite shows a steady evaporation rate of about 5.08 kg−2 m−2 h−1 under 0.1 solar intensity during desalination. The 24 h of indoor desalination experiments proves that both hydrogel is durable and has a steady evaporation performance. The PVA:GA: Au hydrogel (AC) nanocomposite and PVA:GA: Ag hydrogel (AC) nanocomposite hydrogels were characterized by XRD analysis, FE-SEM imaging, UV–Vis and FTIR spectroscopy. The XRD results for PVA:GA: Au hydrogel (AC) nanocomposite and PVA:GA: Ag hydrogel (AC) nanocomposite showed that the amorphous pattern decreased sharply due to a decrease in the PVA peak. Also, the both peaks of Au and Ag with the tetragonal and cubic structures were observed with the preferred direction (110). FE-SEM images of PVA:GA: Au hydrogel (AC) nanocomposite and PVA:GA: Ag hydrogel (AC) nanocomposite showed micro pores on the surface of hydrogels and porous structure of the hydrogel network is formed. Also, the results of FTIR spectroscopy showed that with increasing metal nanoparticles, there is no difference in the type of a factor group and only affects the intensity of the peaks and leads to a little shift of the peaks to the modes of pure PVA. The PVA:GA: Au (Ag) hydrogel (AC) nanocomposite offers a substantial possibility in mitigating freshwater shortages. [ABSTRACT FROM AUTHOR]

Self-assembled gold and silver nanoparticles were fabricated in medium vacuum conditions on Corning glass substrates by means of DC magnetron sputtering. The samples were deposited either at 420 °C or 440 °C, or they were initially deposited at room temperature followed by post annealing. Subsequently, they were covered with three different polymers, namely Polystyrene-block-polybutadiene-blockpolystyrene (PS-b-PBD-b-PS), Polystyrene-co-methyl methacrylate (PS-co-PMMA) and Polystyreneblock-polyisoprene-block-polystyrene (PS-b-PI-b-PS), using spin coating. Localized surface plasmon resonances were recorded in the temperature range of −25 °C–100 °C. We show that the resonance position changes systematically as a function of temperature. Theoretical calculations carried out via the Rigorous Coupled Wave Analysis support the experimental results. Based on these findings, the investigated materials demonstrate potential as components for the development of temperature sensors. [ABSTRACT FROM AUTHOR]

Multiple Fano resonances (mFRs) are arising as a promising optical platform to achieve precise sensing and detection. However, experimentally achieving mFRs by simple structures has remained challenging, which impedes the widespread applications of mFRs. Herein a simple structure composed of a single colloidal metal nanoparticle and a transition metal dichalcogenide flake to simultaneously achieve up to 8 FRs in experiments is demonstrated. Combining theoretical and experimental techniques, that an out‐of‐plane plasmon mode of the metal nanoparticle interferes with the Fabry–Pérot cavity modes from the WS2 flake to form mFRs in the visible region is proved. The simplicity and generality of the method further allow us to systematically study the tunability of the mFRs, in terms of the peak/dip positions and the number of FRs, by changing the structural parameters, which include the thickness of the WS2 flake, size and shape of the plasmonic nanoparticle. In addition, the quality of the mFRs is proved to be adjustable by tuning the reflectivity of the substrate in the system. The highest quality factor and spectral contrast of the achieved resonances are up to ≈180 and ≈0.95, respectively. The simple structure and high‐quality optical modes will prosper applications in precise sensing and light modulation. [ABSTRACT FROM AUTHOR]

Until now, the therapeutic potential of metal nanoparticles (NPs) has received much attention thanks to their unique properties. In addition, natural extracts of plants have shown significant therapeutic ability in various diseases. Therefore, the present study aimed to synthesize AuNPs using aqueous extracts of Hedra helix (Hh-AuNPs), Senna alexandrina (Sa-AuNPs), Thyme vulgaris (Tv-AuNPs) and Tribulus terrestris (Tt-AuNPs) and then investigate their antioxidant and cytotoxic effects on cancerous and normal breast cell lines. For this purpose, the prepared Phyto-NPs were analyzed employing the TEM technique and UV–Vis spectroscopy. The antioxidant activities of all aqueous extracts and the Phyto-NPs were analyzed by FRAP and DPPH assays. Their cytotoxic effects against the MCF-7, MCF-10 and MDA-MB-231 cell lines were also determined using an MTT assay. UV–Vis spectrum of Hh-AuNPs, Sa-AuNPs, Tv-AuNPs and Tt-AuNPs disclosed absorption peaks at wavelengths of 560 ± 5nm, 570 ± 5nm, 550 ± 5nm and 540 ± 5, respectively. TEM image illustrated a spherical shape of Phyto-AuNPs with particle sizes of under 100nm. Phyto-AuNPs demonstrated more antioxidant activities than the plant extracts alone. Moreover, Phyto-AuNPs indicated higher cytotoxic activities against MCF-7 and MDA-MB-231 cell lines compared to plant extracts. This report provides new possibilities for using the above-mentioned aqueous extracts for the green synthesis of AuNPs, which may be applied to future animal breast cancer models or one step higher clinically for breast cancer patients. [ABSTRACT FROM AUTHOR]

Recently, metal nanoparticles synthesized by bio-fabrication methods were being used for various life-saving treatments. In our present study, AuNPs were fabricated using aqueous Panicum Maximum (P. Maximum) leaf extract. The analysis of UV–Visible spectrophotometer indicated the excitation of the formed AuNPs, specifically, a distinct SPR band positioned nearly at 530 nm. The formation of AuNPs with 45–50-nm size range was confirmed by TEM. Also, SAED pattern was utilized to characterize single crystalline nature of the biofabricated AuNPs. Further, the anticancer effects of synthesized AuNPs were studied against HepG2 cells. After incubating HepG2 cells with AuNPs, the amount of cytochrome c, CASP 9/CASP 8/CASP 3/BAX expression level, formation of ROS, and cell viability were analyzed. Outcomes of our study showed a dose determined cytotoxicity and half inhibitory concentration (IC50) of 75 μg/mL for the synthesized AuNPs. Cytotoxicity of AuNPs was accompanied by cell apoptosis and ROS induction in cell line of HepG2. Based on our results, AuNPs could have potential for development of new drugs for therapy of liver hepatocellular carcinoma in nursing care. [ABSTRACT FROM AUTHOR]

Plasmonic nanoparticles exhibit dramatic changes in optical properties depending on their spatial organization. Therefore, the ability to precisely control their assembly structure is important for both fundamental understanding and practical applications. In this personal account, we describe a templated surfactant‐assisted seed‐growth method to synthesize core–shell‐type gold nanoparticle assemblies with controllable surface morphologies and optical properties. This approach provides a simple procedure for simultaneous growth and assembly of metal nanoparticles on polymer templates, producing well‐defined nanostructures such as spiky nanoshells and raspberry‐like metamolecules with useful and interesting optical properties, such as strong and uniform surface‐enhanced Raman scattering and metamaterial properties. We discuss the factors that control the morphology and collective properties, describe the design rules acquired from the system, and suggest future directions of this research area. [ABSTRACT FROM AUTHOR]

BACKGROUND: Biogenic metal nanoparticle‐modified electrodes have a promising prospect for improving the efficiency of microbial fuel cells (MFCs) for hexavalent chromium (Cr(VI))‐containing wastewater treatment. In this study, a graphene (GO) electrode was modified with chemical gold nanoparticles (ChemAu) and biogenic gold nanoparticles (BioAu), respectively, and the two modified electrodes were then used as MFC biocathode electrodes to treat Cr(VI)‐containing wastewater. RESULTS: The results demonstrated that the BioAu/GO biocathode‐based MFC obtained the highest power density (95.78 ± 1.11 mW m−2) and Cr(VI) removal rate (2.17 ± 0.51 mg L−1 h), which were 13.19 and 1.03 times higher than those of the graphite paper biocathode‐based MFC, respectively. The Cr(VI) removal efficiency of the BioAu/GO biocathode‐based MFC under close‐circuit condition reached 87.61 ± 0.19%, which was 3.74 times higher than that recorded under open‐circuit conditions, indicating the critical role of the bioelectrochemical reduction reaction mediated by the BioAu/GO biocathode on Cr(VI) removal. CONCLUSION: The BioAu/GO electrode first confirmed its superior performance to the ChemAu/GO electrode in Cr(VI)‐reducing MFCs due to its excellent material properties. This study provides a technical reference for the exploration of efficient bioelectrode materials based on biogenic metal nanoparticles for MFCs to treat recalcitrant pollutant‐containing wastewater. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

4-nitrophenol (4-NP) is a frequently encountered toxic phenolic organic pollutant in water. It is important to develop a simple method to treat 4-NP. Small and monodispersed gold nanoparticles often have good catalytic performance of 4-NP. Hemoglobin (Hb) is a kind of common and important protein in organisms. Herein, highly biocompatible bovine hemoglobin-stabilized gold nanoparticles (Aun-Hb NPs) were synthesized using hemoglobin as a biological template. Then, the size, zeta potential, and composition of Aun-Hb NPs were investigated by transmission electron microscopy, dynamic light scattering, and X-ray photoelectron spectroscopy. The Aun-Hb NPs with small gold nanoparticles of about 1.4–2.4 nm had good catalytic capabilities in reducing 4-NP to form 4-aminophenol. Au20-Hb NPs demonstrated superior catalytic efficiency in the reduction of 4-NP when compared to other nanoparticles. Moreover, as-synthesized Au20-Hb NPs exhibited excellent biocompatibility through the MTT experiment. The method of preparation of gold nanoparticles offers one way to prepare metal nanoparticles for good potential catalytic applications of gold nanoparticles. [ABSTRACT FROM AUTHOR]

We recently found that polyvinylpyrrolidone (PVP)-protected metal nanoparticles dispersed in water/butanol mixture spontaneously float to the air/water interface and form two-dimensional assemblies due to classical surface excess theory and Rayleigh–Bénard–Marangoni convection induced by butanol evaporation. In this study, we found that by leveraging this principle, a unique structure is formed where hetero gold nanospheres (AuNPs)/gold nanostars (AuNSs) complexes are dispersed within AuNP two-dimensional assemblies, obtained from a mixture of polyvinylpyrrolidone-protected AuNPs and AuNSs that interact electrostatically with the AuNPs. These structures were believed to form as a result of AuNPs/AuNSs complexes formed in the water/butanol mixture floating to the air/water interface and being incorporated into the growth of AuNP two-dimensional assemblies. These structures were obtained by optimizing the amount of mixed AuNSs, with excessive addition resulting in the formation of random three-dimensional network structures. The AuNP assemblies dispersed with AuNPs/AuNSs complexes exhibited significantly higher Raman (surface-enhanced resonance Raman scattering: SERRS) activity compared to simple AuNP assemblies, while the three-dimensional network structure did not show significant SERRS activity enhancement. These results demonstrate the excellent SERRS activity of AuNP two-dimensional assemblies dispersed with hetero AuNPs/AuNSs complexes. [ABSTRACT FROM AUTHOR]

The branched structures of dendronized polymers can provide good steric stabilization for metal nanoparticle catalysts. In this work, an amphiphilic dendronized copolymer containing hydrophilic branched triethylene glycol moieties and hydrophobic branched ferrocenyl moieties is designed and prepared by one-pot ring-opening metathesis polymerization, and is used as the stabilizer for metal (Au, Ag and Pd) nanoparticles. These metal nanoparticles (Au nanoparticles: 3.5 ± 3.0 nm; Ag nanoparticles: 7.2 ± 4.0 nm; Pd nanoparticles: 2.5 ± 1.0 nm) are found to be highly active in both the 4-nitrophenol reduction and Suzuki–Miyaura reactions. In the 4-nitrophenol reduction, Pd nanoparticles have the highest catalytic ability (TOF: 2060 h−1). In addition, Pd nanoparticles are also an efficient catalyst for Suzuki–Miyaura reactions (TOF: 1980 h−1) and possess good applicability for diverse substrates. The amphiphilic dendronized copolymer will open a new door for the development of efficient metal nanoparticle catalysts. [ABSTRACT FROM AUTHOR]

Gold nanoparticles (AuNPs) are arguably the most promising in terms of application among the noble metal nanoparticles. As such, researchers have dedicated a considerable amount of energy towards the synthesis of novel gold nanoparticles with different morphology and size, which in turn affect its potential application. This study synthesized novel spherical-shaped AuNPs via green reduction of gold ion in an aqueous solution of HAuCl4.3H2O in the presence of trimethyl chitosan as a stabilizing agent and pressurized H2 gas as a reducing agent on an ice water. The size, morphology, chemical composition, chemical environment and optical activities were examined by scanning electron microscope (SEM), high-resolution transmission electron microscope (HRTEM), x-ray photoelectron spectroscopy (XPS), and ultraviolet–visible spectroscopy (Uv–Visible), respectively. The average particle size of AuNPs is 37 nm while HR-TEM revealed a unique spherical morphology. The Tauc’s plot calculation revealed a band gap of 5.0 eV. This unique morphology and optical local field enhancement in plasmonic nanocomposites could be suitable alternative for conducting devices and photocatalysis. [ABSTRACT FROM AUTHOR]

Polymer nanocomposite materials with catalytic activity were designed via modification of MF-4SK ion-exchange membranes with Au and Ag nanoparticles obtained according to various synthetic methods in reverse micellar solutions. A sufficient transparency of the films allowed us to detect nanoparticles in the films using UV–Vis spectrophotometry, monitoring changes in the content of metal nanoparticles in the reverse micellar solution. A different mechanism of interaction of Au and Ag nanoparticles obtained by the same synthetic method with the MF-4SK film upon their contact with its surface was discovered, the destruction of nanoparticles was observed, and the influence of mechanism of primary acts in the formation of metal nanoparticles in reverse micellar solutions on their adsorption properties was confirmed. The highest concentration of gold nanoparticles was found in films immersed in reverse micellar solutions at the time of their exposure to ionizing radiation. [ABSTRACT FROM AUTHOR]

The early detection of procalcitonin (PCT) is crucial for diagnosing bacterial infections due to its high sensitivity and specificity. While colloidal gold colorimetric and immune-chemiluminescence methods are commonly employed in clinical detection, the former lacks sensitivity, and the latter faces challenges with a brief luminescence process and an elevated background. Here, we introduce a novel approach for the quantitative analysis of PCT using surface-enhanced Raman spectroscopy (SERS), leveraging the enhanced properties of metal nanoparticles. Simultaneously, we employed a magnetic nanoparticle coating and surface biofunctionalization modification to immobilize PCT-trapping antibodies, creating the required immune substrates. The resulting magnetic nanoparticles and antibody complexes, acting as carriers and recognition units, exhibited superparamagnetism and the specific recognition of biomarkers. Then, this complex efficiently underwent magnetic separation with an applied magnetic field, streamlining the cumbersome steps of traditional ELISA and significantly reducing the detection time. In conclusion, the exploration of immunomagnetic bead detection technology based on surface-enhanced Raman spectroscopy holds crucial practical significance for the sensitive detection of PCT. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

We prepared metal alloy nanoparticles by pulsed laser ablation of the boundary between jointed target metal plates of Au and Ag in purified water. When the spot size radius of the focused laser on the target was 2.5 mm, separate Au nanoparticles and Ag nanoparticles were mainly observed with slight alloying. In contrast, when the spot size radius was 0.25 mm, the ejected Au and Ag atoms were found to be more mixed, efficiently forming Au and Ag alloy nanoparticles. The mixing distance of Au and Ag atoms was estimated to be ∼0.5 mm. The dynamics of the plasma plume and the cavitation and their interaction with Au and Ag atoms were quite complex. Hence, we assumed that during plasma plume formation and cavitation formation, Au and Ag atoms diffuse in the plasma plume and cavitation as a uniform medium with a maximum temperature and minimum viscosity. It was suggested that the fast mixing of Au and Ag atoms occurred inside the plasma plume, taking the high temperature, several thousand K of the plasma plume into account. Moreover, the mixing was promoted by the overlapping of plasma plumes, which were generated on Au and Ag plates separately, owing to explosive plasma motions. Then, the alloy nanoparticles were formed in the cavitation bubble where Au and Ag atoms were spatially distributed by plasma plumes. The mixing of the atoms in the cavitation bubble was not likely based on the mixing distance. [ABSTRACT FROM AUTHOR]

Localized surface plasmon resonances on noble metal nanoparticles (NPs) can efficiently drive reactions of adsorbed ligand molecules and provide versatile opportunities in chemical synthesis. The driving forces of these reactions are typically elevated temperatures, hot charge carriers, or enhanced electric fields. In the present work, dehalogenation of halogenated thiophenols on the surface of AuNPs has been studied by surface enhanced Raman scattering (SERS) as a function of the photon energy to track the kinetics and identify reaction products. Reaction rates are found to be surprisingly similar for different halothiophenols studied here, although the bond dissociation energies of the C–X bonds differ significantly. Complementary information about the electronic properties at the AuNP surface, namely, work-function and valence band states, has been determined by x-ray photoelectron spectroscopy of isolated AuNPs in the gas-phase. In this way, it is revealed how the electronic properties are altered by the adsorption of the ligand molecules, and we conclude that the reaction rates are mainly determined by the plasmonic properties of the AuNPs. SERS spectra reveal differences in the reaction product formation for different halogen species, and, on this basis, the possible reaction mechanisms are discussed to approach an understanding of opportunities and limitations in the design of catalytical systems with plasmonic NPs. [ABSTRACT FROM AUTHOR]

Introduction: Microorganisms originating from the marine environment, such as bacteria, fungi, and algae, are deliberately employed in the production of nanoparticles on account of the wide array of bioactive compounds they produce. Methods: Cell-free aqueous extracts of marine Bacillus subtilis (CBPPR1) were used to synthesise AuNPs (CBPPR1AuNPs) and AgNPs (CBPPR1AgNPs). Zetasizer Nano ZS (Malvern Instruments) zeta size and zeta potential, field emission and transmission scanning electron microscopy (FE-SEM and HR-TEM), UV-visible (UV-Vis), X-ray diffraction (XRD), Fourier transform infrared (FT-IR), and EDAX were used to characterize biogenically synthesized nanoparticles (NPs). Their antibacterial activities against Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus were investigated. The anticancer efficacy of CBPPR1Au and AgNPs was investigated in human colorectal adenocarcinoma cell lines (HT-29, HT-116). CBPPR1AgNPs formulation was studied in vitro and invivo rat models. The assessment focused on its efficacy in wound healing and antibacterial capabilities, comparing them against a commercial product. To determine the effectiveness of CBPPR1AgNPs in wound healing, a cutaneous wound model was employed, which included infection with S. aureus. Results and discusion: CBPPR1Au and AgNPs significantly inhibited the growth of S aureus at MIC of 125 µg (CBPPR1AuNPs) and 62.5 µg (CBPPR1AgNPs) respectively. FE-SEM and HR-TEM observations confirmed that NPs caused bacterial cell leakage, damage, and shrinkage. Cancer cell viability was reduced upon treatment with increasing concentrations of CBPPR1Au and AgNPs, and apoptosis was increased in cells treated with CBPPR1Au and AgNPs relative to untreated cells (p < 0.001). CBPPR1Au and AgNPs showed significant cytotoxic activity against HT-29 (15.5 M) and HT-116 (62.5 M) cells. In-vivo experiments on rats showed minimal pus formation in groups CBPPR1AgNPs (62.5 µg/ml) G2, CBPPR1AgNPs (125 µg/ml) G3, and silver sulfadiazine G4, indicating the effective control of infections. CBPPR1AgNPs-treated wounds showed complete closure, whereas untreated G1 wounds remained unhealed. Histopathological analysis showed no adverse effects of CBPPR1AgNPs on kidneys and livers of rats. These findings suggest that CBPPR1AgNPs play a pivotal role in wound healing because of their potent antibacterial properties. [ABSTRACT FROM AUTHOR]

• Eco-friendly synthesis of gold and silver nanoparticles using Solanum nigrum root extract, characterized using various techniques (XRD, UV–Vis, FTIR, TEM, SAED and EDAX). • Dose-dependent lung cancer activity is evaluated. • Environmental remediation against methylene blue and methylene orange dyes. • Antibacterial assessment targeting Salmonella typhi and Staphylococcus aureus. In this study, we utilized the natural reducing and stabilizing properties of Solanum nigrum root (SNR) to create nanoscale gold and silver particles, and explored their potential for anticancer, antibacterial, and photocatalytic applications. Natural source-based nanoparticle preparation was achieved by combining root extract with aqueous solutions of chloroauric acid and silver nitrate. The produced nanoparticles were recognized by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet-Visible spectroscopy (UV–VIS), Transmission Electron Microscopy (TEM), Selected Area Electron Diffraction (SAED), and Energy-Dispersive X-ray spectroscopy (EDAX). Resulting nanoscale particles had diameters of 22.35 nm and 11.85 nm for gold and silver nanoparticles synthesized using a 5 ml SNR extract. While 16.06 nm and 8.72 nm sized gold and silver nanoparticles were synthesized using a 10 ml SNR extract. Their antibacterial properties were tested against Salmonella typhi and Staphylococcus aureus. Staphylococcus aureus showed the highest inhibitory activity. To evaluate the effectiveness of NPs in treating lung cancer, in vitro experiments were performed utilising the A549 cell line. The remarkable performance of gold and silver nanoparticles in the photocatalytic degradation of methylene blue and methylene orange was demonstrated. This research contributes to Solanum nigrum -derived metal nanoparticles and their multifunctional capabilities, paving the way for new prospects in cancer therapeutics, antibacterial agents, and environmental remediation strategies. [ABSTRACT FROM AUTHOR]

In this study, CdS quantum dots (QDs) capped with benzyl mercaptan (thiol) were prepared by microwave irradiation technique. The shape, size, morphology, and spectral properties of thiol-capped CdS QDs were characterized with transmission electron microscopy (TEM), scanning electron microscopy (SEM), UV-vis absorption, and photoluminescence (PL) spectrometry. The photophysical properties of synthesized thiol-capped CdS QDs in the presence of different amounts of gold nanoparticles (AuNPs) have been investigated, exhibiting strong PL quenching. The amount of fluorescence quenching was found to be dependent on the concentration of metal nanoparticles. A Stern-Volmer kinetics model was used to analyze the observed quenching mechanism as a function of the quencher (AuNPs) concentration. The Stern-Volmer plot along with the absorption spectra of thiol-capped CdS QDs in the absence and presence of AuNPs suggest the dynamic (collision) nature of quenching and rule out the possibility of static quenching. The energy transfers from QDs to Au NPs, and hence the quenching of QDs emissions provides new insight into designing novel optical-based materials and the development of FRET-based bionanosensors and phototherapeutic applications. [ABSTRACT FROM AUTHOR]

The present study investigates the synthesis of vertically aligned MnO2 nanowires (NW) decorated with gold (Au) and silver (Ag) nanoparticles (NP) via the glancing angle deposition (GLAD) technique without a need for a catalyst. The cross-sectional field emission scanning electron microscopy (FESEM) image and energy-dispersive X-ray spectroscopy (EDS) confirm the successful adornment of Ag NP and Au NP on the top surface of MnO2 NW. Elemental mapping has verified the presence of manganese (Mn), oxygen (O), silicon (Si), Ag, and Au within the sample. X-ray diffraction (XRD) patterns reveal the polycrystalline growth of the MnO2 film with the preferred orientation. AFM reveals that the surface roughness of Au NP/MnO2 NW is more than Ag NP/MnO2 NW. The measured water contact angles of Au NP/MnO2 NW, Ag NP/MnO2 NW, and MnO2 NW were 125° and 113°, respectively. Ag NP/MnO2 NW showed more hydrophilic properties under UV illumination than Au NP/MnO2 NW owing to the efficient separation of photogenerated electron–hole pairs. Ag NP/MnO2 NW's higher photocatalytic activity than Au NP/MnO2 NW is attributed to the increased light absorption of the Ag NP in the UV region. The overall enhancement after decorating the noble metal NP on MnO2 NW could open new avenues for self-cleaning applications. [ABSTRACT FROM AUTHOR]

This review considers the fundamental dynamic processes involved in the laser heating of metal nanoparticles and their subsequent cooling. Of particular interest are the absorption of laser energy by nanoparticles, the heating of a single nanoparticle or an ensemble thereof, and the dissipation of the energy of nanoparticles due to heat exchange with the environment. The goal is to consider the dependences and values of the temperatures of the nanoparticles and the environment, their time scales, and other parameters that describe these processes. Experimental results and analytical studies on the heating of single metal nanoparticles by laser pulses are discussed, including the laser thresholds for initiating subsequent photothermal processes, how temperature influences the optical properties, and the heating of gold nanoparticles by laser pulses. Experimental studies of the heating of an ensemble of nanoparticles and the results of an analytical study of the heating of an ensemble of nanoparticles and the environment by laser radiation are considered. Nanothermometry methods for nanoparticles under laser heating are considered, including changes in the refractive indices of metals and spectral thermometry of optical scattering of nanoparticles, Raman spectroscopy, the thermal distortion of the refractive index of an environment heated by a nanoparticle, and thermochemical phase transitions in lipid bilayers surrounding a heated nanoparticle. Understanding the sequence of events after radiation absorption and their time scales underlies many applications of nanoparticles. The application fields for the laser heating of nanoparticles are reviewed, including thermochemical reactions and selective nanophotothermolysis initiated in the environment by laser-heated nanoparticles, thermal radiation emission by nanoparticles and laser-induced incandescence, electron and ion emission of heated nanoparticles, and optothermal chemical catalysis. Applications of the laser heating of nanoparticles in laser nanomedicine are of particular interest. Significant emphasis is given to the proposed analytical approaches to modeling and calculating the heating processes under the action of a laser pulse on metal nanoparticles, taking into account the temperature dependences of the parameters. The proposed models can be used to estimate the parameters of lasers and nanoparticles in the various application fields for the laser heating of nanoparticles. HIGHLIGHTS: • Analytical modeling of heating of a single nanoparticle or an ensemble thereof by laser radiation. • Nanothermometry methods for nanoparticle heating by laser radiation. • Applications of laser heating of nanoparticles in nanomedicine, nanoparticle processing, catalysis, etc. [ABSTRACT FROM AUTHOR]

A surface-enhanced Raman scattering (SERS) method for measuring nitrate nitrogen in aquaculture water was developed using a substrate of β-cyclodextrin-modified gold nanoparticles (SH-β-CD@AuNPs). Addressing the issues of low sensitivity, narrow linear range, and relatively poor selectivity of single metal nanoparticles in the SERS detection of nitrate nitrogen, we combined metal nanoparticles with cyclodextrin supramolecular compounds to prepare a AuNPs substrate enveloped by cyclodextrin, which exhibits ultra-high selectivity and Raman activity. Subsequently, vanadium(III) chloride was used to convert nitrate ions into nitrite ions. The adsorption mechanism between the reaction product benzotriazole (BTAH) of o-phenylenediamine (OPD) and nitrite ions on the SH-β-CD@AuNPs substrate was studied through SERS, achieving the simultaneous detection of nitrate nitrogen and nitrite nitrogen. The experimental results show that BTAH exhibits distinct SERS characteristic peaks at 1168, 1240, 1375, and 1600 cm−1, with the lowest detection limits of 3.33 × 10−2, 5.84 × 10−2, 2.40 × 10−2, and 1.05 × 10−2 μmol/L, respectively, and a linear range of 0.1–30.0 μmol/L. The proposed method provides an effective tool for the selective and accurate online detection of nitrite and nitrate nitrogen in aquaculture water. [ABSTRACT FROM AUTHOR]

Highly transparent, conductive nanosheets are extremely attractive for advanced opto-electronic applications. Previously, we have demonstrated that transparent, conductive Au nanosheets can be prepared by UV irradiation of Au nanoparticle (AuNP) monolayers spread on water, which serves as the subphase. However, thick Au nanosheets cannot be fabricated because the method is not applicable to large Au NPs. Further, in order to fabricate nanosheets with different thicknesses and compositions, it is necessary to prepare the appropriate NPs. A strategy is needed to produce nanosheets with different thicknesses and compositions from a single type of metal NP monolayer. In this study, we show that this UV irradiation technique can easily be extended as a nanosheet modification method by using subphases containing metal ions. UV irradiation of 4.7 nm AuNP monolayers on 480 µM HAuCl4 solution increased the thickness of Au nanosheets from 3.5 nm to 36.5 nm, which improved conductivity, but reduced transparency. On the other hand, the use of aqueous AgNO3 and CH3COOAg solutions yielded Au-Ag hybrid nanosheets; however, their morphologies depended on the electrolytes used. In Au-Ag nanosheets prepared on aqueous 500 µM AgNO3, Au and Ag metals are homogeneously distributed throughout the nanosheet. On the other hand, in Au-Ag nanosheets prepared on aqueous 500 µM CH3COOAg, AuNPs still remained and these AuNPs were covered with a Ag nanosheet. Further, these Au-Ag hybrid nanosheets had high conductivity without reduced transparency. Therefore, this UV irradiation method, modified by adding metal ions, is quite effective at improving and diversifying properties of Au nanosheets. [ABSTRACT FROM AUTHOR]

Owing to their remarkable properties, gold nanoparticles are applied in diverse fields, including catalysis, electronics, energy conversion and sensors. However, for catalytic applications of colloidal gold nanoparticles, the trade-off between their reactivity and stability is a significant concern. Here we report a universal approach for preparing stable and reactive colloidal small (~3 nm) gold nanoparticles by using multi-dentate polyoxometalates as protecting agents in non-polar solvents. These nanoparticles exhibit exceptional stability even under conditions of high concentration, long-term storage, heating and addition of bases. Moreover, they display excellent catalytic performance in various oxidation reactions of organic substrates using molecular oxygen as the sole oxidant. Our findings highlight the ability of inorganic multi-dentate ligands with structural stability and robust steric and electronic effects to confer stability and reactivity upon gold nanoparticles. This approach can be extended to prepare metal nanoparticles other than gold, enabling the design of novel nanomaterials with promising applications. For catalytic nanoparticles there is often a trade-off between stability and activity. Here the authors report a route to ultra-stable and catalytically active colloidal small (~3 nm) gold nanoparticles using multi-dentate polyoxometalates as protecting agents in nonpolar solvents. [ABSTRACT FROM AUTHOR]

Increasing climatic instability, along with increasing technogenic pressure on the natural environment, necessitate the search for new approaches to increasing the resistance of wheat to abiotic factors, primarily to low temperature. A promising direction is the use of metal nanoparticles, which have the ability to positively influence plant metabolism in low concentrations. Due to their small size (less than 100 nm) and special physicochemical, optical, and electrical properties, nanoparticles penetrate cellular barriers, spread throughout the plant organism, affecting almost all processes in it. With wheat as an example (Triticum aestivum L., variety Zlata), it was shown for the first time that gold nanoparticles (GNPs) can act as adaptogens, increasing the cold resistance of plants. The study used priming—soaking of seeds in GNP solutions with concentrations 5–50 μg/mL for 24 h. The plants grown from seeds treated with GNPs differed from the control (untreated) ones in a number of physiological, biochemical, and molecular genetic parameters. Their growth processes and activity of the photosynthetic apparatus were significantly enhanced, and the expression of genes encoding large (rbcL) and small (rbcS) Rubisco subunits, as well as COR genes, Wcor726 and Wcor15, were increased. Moreover, wheat plants obtained from GNP-treated seeds differed from control ones in their increased resistance to low temperatures, and the effect was manifested both under control conditions and after low-temperature hardening. Concentration tests showed that the maximum effect was achieved when using GNPs at a concentration of 10 μg/mL. It is concluded that GNPs are able to influence plant metabolism and the expression of stress response genes, which leads to a significant increase in cold resistance. Possible mechanisms of GNP action on low temperature resistance are discussed. [ABSTRACT FROM AUTHOR]

Layered two-dimensional materials, whose properties dramatically differ from their bulk precursors, are of great theoretical and applied importance. Recently, a layered 2D material, an analog of a natural mineral, valleriite, in which quasi-monoatomic Cu−Fe−S sheets alternate with brucite-like ones, has been prepared using a simple hydrothermal synthesis procedure. The features of the electronic structure of these materials make it possible to propose them as new materials for a wide field of applications such as (electro)photocatalysis, high-capacity batteries, etc. In this work, nanocomposite materials have been prepared via immobilization of gold nanoparticles (AuNPs) from citrate hydrosols on the surface of the synthesized valleriites having different compositions of hydroxide layers, which control the surface charge density. According to X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), energy-dispersive X-ray microanalysis (EDX), and selected area electron diffraction (SAED) data, AuNPs are immobilized on valleriite nanoflakes, which have lateral sizes of 150–200 nm and thicknesses of several tens of nanometers, as isolated metal nanoparticles with an average diameter of 11 nm. A small amount of aggregates indicates a high affinity of AuNPs for the valleriite surface. The amounts of immobilized gold are the same on all studied valleriites (~0.2%). This finding may be related to the simultaneous sorption of free citrate ions from the AuNP hydrosols, with these ions, according to zeta potential measurements, charging the surfaces of all studied valleriite samples to nearly the same negative value of –40 mV. According to the XPS data, the AuNPs immobilization markedly decreases the magnesium and oxygen contents on the surfaces of the synthesized valleriites due to the partial degradation/dissolution of the brucite layer. In addition, the amount of Fe3+ ions bound to OH groups decreases with a simultaneous increase in the fraction of Fe3+–O species. The TEM data have confirmed the preservation of the layered structure of valleriites after the immobilization of AuNPs. [ABSTRACT FROM AUTHOR]

The effect of gold and silver nanoparticles with plasmon resonance on the chemiluminescence of luminol in an oxidizing environment was studied. It has been shown that when a colloidal solution of metal nanoparticles is added to luminol, the intensity of chemiluminescence caused by the presence of hydrogen peroxide and sodium hypochlorite increases and can be easily recorded at a pH level characteristic of biological media close to neutral, at which chemiluminescence is weak in the absence of metal nanoparticles. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs) are involved in the modulation of pathogenic genes by binding to their mRNA sequences' 3′ untranslated regions (3′UTR). Interleukin-6 (IL-6) is known to promote cancer progression and treatment resistance. In this study, we aimed to explore the therapeutic effects of gold nanoparticles (GNP) against IL-6 overexpression and the modulation of miRNA-26a-5p in breast cancer (BC) cells. GNP were synthesized using the trisodium citrate method and characterized through UV-Vis spectroscopy, dynamic light scattering (DLS), and transmission electron microscopy (TEM). To predict the binding of miR-26a-5p in the IL-6 mRNA's 3′UTR, we utilized bioinformatics algorithms. Luciferase reporter clone assays and anti-miRNA-26a-5p transfection were employed to validate the binding of miR26a-5p in the IL-6 mRNA's 3′UTR. The activity of RelA and NF-κBp50 was assessed and confirmed using Bay 11-7082. The synthesized GNP were spherical with a mean size of 28.3 nm, exhibiting high stability, and were suitable for BC cell treatment. We found that miR-26a-5p directly regulated IL-6 overexpression in MCF-7 cells activated with PMA. Treatment of MCF-7 cells with GNP resulted in the inhibition of IL-6 overexpression and secretion through the increase of miR26a-5p. Furthermore, GNP deactivated NF-κBp65/NF-κBp50 transcription activity. The newly engineered GNP demonstrated safety and showed promise as a therapeutic approach for reducing IL-6 overexpression. The GNP suppressed IL-6 overexpression and secretion by deactivating NF-κBp65/NF-κBp50 transcription activity and upregulating miR-26a-5p expression in activated BC cells. These findings suggest that GNP have potential as a therapeutic intervention for BC by targeting IL-6 expression and associated pathways. [ABSTRACT FROM AUTHOR]

Antimicrobial resistance (AMR) has become an alarming threat to the successful treatment of rapidly growing bacterial infections due to the abuse and misuse of antibiotics. Traditional antibiotics bear many limitations, including restricted bioavailability, inadequate penetration and the emergence of antimicrobial-resistant microorganisms. Recent advances in nanotechnology for the introduction of nanoparticles with fascinating physicochemical characteristics have been predicted as an innovative means of defence against antimicrobial-resistant diseases. The use of nanoparticles provides several benefits, including improved tissue targeting, better solubility, improved stability, enhanced epithelial permeability and causes minimal side effects. However, except for gold nanoparticles (AuNPs), the biological safety of the majority of metal nanoparticles remains a serious problem. AuNPs appear to be promising for drug delivery and medicinal applications because of their minimal toxicity, biocompatibility, functional flexibility, chemical stability and versatile biological activities, such as their antiviral, antifungal, anti-inflammatory and antimicrobial properties. Hence, we are focusing on the gold nanoparticles possessing antimicrobial activity in this article. This review will cover recent strategies in the preparation of gold nanoparticles, with special emphasis placed on antibiotics-coated AuNPs with enhanced antimicrobial properties and how they fight against disease-causing bacteria and eradicate biofilms, along with their activities and physicochemical properties. [ABSTRACT FROM AUTHOR]

Developing green fibrous materials with uniformly distributed metal nanoparticles for highly efficient and recyclable catalysis remains a major challenge. Herein, we developed a simple, effective, and green method to immobilize gold nanoparticles (AuNPs) on polydopamine (PDA)-functionalized silk fibers (SFs) for efficient catalytic reduction of 4-nitrophenol (4-NP). The density and size of AuNPs on the PDA-coated SFs can be tuned by adjusting precursor concentration and synthesis duration, respectively. The AuNPs-PDA-SFs catalysts prepared under optimized conditions could catalyze the reduction of 4-NP, 4-nitroaniline (4-NA), and 4-amino-3-nitrophenol (4-A-3-NP) at the apparent rate constants of 0.087, 0.091, and 0.063 min−1, respectively. After six rounds of flow-through reduction of 4-NP, the AuNPs-PDA-SFs could maintain a 4-NP conversion rate greater than 92%, indicating their superior reusability and consistent catalytic activity. Due to the protein properties of SFs, the AuNPs-PDA-SFs can be degraded by enzymes and alkali solutions. This work may provide new insights for designing advanced fiber-supported recyclable catalysts with high catalytic performance and reusability in wastewater treatment. [ABSTRACT FROM AUTHOR]

The conjugation of DNA molecules with metal or metal-containing nanoparticles (M/MC NPs) has resulted in a number of new hybrid materials, enabling a diverse range of novel biological applications in nanomaterial assembly, biosensor development, and drug/gene delivery. In such materials, the molecular recognition, gene therapeutic, and structure-directing functions of DNA molecules are coupled with M/MC NPs. In turn, the M/MC NPs have optical, catalytic, pore structure, or photodynamic/photothermal properties, which are beneficial for sensing, theranostic, and drug loading applications. This review focuses on the different DNA functionalization protocols available for M/MC NPs, including gold NPs, upconversion NPs, metal–organic frameworks, metal oxide NPs and quantum dots. The biological applications of DNA-functionalized M/MC NPs in the treatment or diagnosis of cancers are discussed in detail. [ABSTRACT FROM AUTHOR]

Globally, cardiovascular diseases (CVDs) are the leading cause of death and disability. While there are many therapeutic alternatives available for the management of CVDs, the majority of classic therapeutic strategies were found to be ineffective at stopping or significantly/additionally slowing the progression of these diseases, or they had unfavorable side effects. Numerous metal-based nanoparticles (NPs) have been created to overcome these limitations, demonstrating encouraging possibilities in the treatment of CVDs due to advancements in nanotechnology. Metallic nanomaterials, including gold, silver, and iron, come in various shapes, sizes, and geometries. Metallic NPs are generally smaller and have more specialized physical, chemical, and biological properties. Metal-based NPs may come in various forms, such as nanoshells, nanorods, and nanospheres, and they have been studied the most. Massive potential applications for these metal nanomaterial structures include supporting molecular imaging, serving as drug delivery systems, enhancing radiation-based anticancer therapy, supplying photothermal transforming effects for thermal therapy, and being compounds with bactericidal, fungicidal, and antiviral qualities that may be helpful for cardiovascular diseases. In this context, the present paper aims to review the applications of relevant metal and metal oxide nanoparticles in CVDs, creating an up-to-date framework that aids researchers in developing more efficient treatment strategies. [ABSTRACT FROM AUTHOR]

Periodontitis, one of the most prevalent dental diseases, causes the loss of bone and gum tissue that hold teeth in place. Several bacteria, commonly present in clinically healthy oral cavities, may induce and perpetuate periodontitis when their concentration rises in the gingival sulcus. Antibacterial effect against various Gram-negative and Gram-positive bacteria, including pathogenic and drug-resistant ones, has been shown for several distinct transient metal and metal oxide NPs. Therefore, NPs may be used in biomedicine to treat periodontal problems and in nanotechnology to inhibit the development of microorganisms. Instead of using harmful chemicals or energy-intensive machinery, biosynthesis of metal and metal oxide nanoparticles (NPs) has been suggested. To produce metal and metal oxide NPs, the ideal technique is "Green" synthesis because of its low toxicity and safety for human health and the environment. Gold NPs (AuNPs) appear to be less toxic to mammalian cells than other nanometals because their antibacterial activity is not dependent on reactive oxygen species (ROS). AgNPs also possess chemical stability, catalytic activity, and superior electrical and thermal conductivity, to name a few of their other advantageous characteristics. It was observed that zinc oxide (ZnO) NPs and copper (Cu) NPs exhibited discernible inhibitory effects against gram-positive and gram-negative bacterial strains, respectively. ZnO NPs demonstrated bactericidal activity against the microorganisms responsible for periodontitis. Medications containing magnetic NPs are highly effective against multidrug-resistant bacterial and fungal infections. The titanium dioxide (TiO2) NPs are implicated in elevating salivary peroxidase activity in individuals diagnosed with chronic periodontitis. Furthermore, specific metallic NPs have the potential to enhance the antimicrobial efficacy of periodontitis treatments when combined. Therefore, these NPs, as well as their oxide NPs, are only some of the metals and metal oxides that have been synthesized in environmentally friendly ways and shown to have therapeutic benefits against periodontitis. [ABSTRACT FROM AUTHOR]

The biosynthesis of nanoparticles has drawn fervent interest because of its environmental friendliness and broad applications in biomedicine. In this study, gold nanoparticles (AuNPs) were synthesized employing Satureja Khuzistanica Jamzad (SKJ) extract (AuNPs-EX) and essential oils (AuNPs-EO). Accordingly, physicochemical characterization of the biosynthesized AuNPs was performed using conventional methods, including visual observation, UV–Vis spectrophotometry, particle size analysis, zeta potential, XRD, FTIR, and FESEM. The results showed the successful formation of AuNPs with cubic and spherical morphologies and sizes of 244.96 and 252.83 nm for AuNPs-EX and AuNPs-EO, respectively. Additionally, AuNPs showed long-term stability, as reflected by their high negative surface charge. Also, the antibacterial and antifungal properties of AuNPs were demonstrated using a microbroth dilution assay against three G+ bacterial standard strains (Bacillus cereus, Staphylococcus aureus, and Staphylococcus saprophyticus), three G− bacterial standard strains (Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae), and three fungal standard strains (Candida albicans, Aspergillus flavus, and Aspergillus fumigatus). Our results indicated that AuNPs-EO exhibited higher antibacterial and antifungal properties than SKJ essential oils. Taken together, the biosynthesis of AuNPs using SKJ may provide an eco-friendly approach for preparing metal nanoparticles and is a promising candidate for controlling infectious diseases. [ABSTRACT FROM AUTHOR]

This document is a correction notice for an article titled "Exploiting the high conjugation capacity of creatinine on 3,3'-dithiodipropionic acid di(N-hydroxysuccinimide ester) functionalized gold nanoparticles towards sensitive determination of mercury (II) ion in water" published in the Journal of Nanostructure in Chemistry. The correction addresses errors in the TEM image and FTIR spectra included in the original article. The authors apologize for the mistakes and state that the corrected figures do not change the results and conclusions of the paper. The correction notice includes the corrected TEM image and FTIR spectra. The publisher, Springer Nature, remains neutral regarding jurisdictional claims and institutional affiliations. [Extracted from the article]

Plasmon–exciton interactions between noble metal nanostructures and two-dimensional transition metal dichalcogenides have drawn great interest due to their significantly enhanced optical properties. Plasmon resonance of noble metal nanoparticles and plasmon–exciton interactions are strongly dependent on the particle morphology. Single-particle spectroscopic studies can overcome the ensemble average effects of sample inhomogeneity to unambiguously reveal the effects of the particle morphology. In this work, plasmon modulated emission of MoS2 in various plasmon–MoS2 hybrid structures has been studied on the single-particle level. Gold (Au) nanoantennas of different shapes including nanosphere, nanorod, nanocube, and nanotriangle with similar overall dimensions, which have different sharp tips and contact areas with MoS2, have been chosen to explore the particle shape effects. Different extent of enhancement in photoluminescence (PL) of MoS2 was observed for Au nanoantennas of different shapes. It was found that Au nanotriangles gave the highest enhancement factor, while Au nanospheres gave the lowest enhancement factor. The numerical simulation results show that the dominant contribution arises from an increased quantum yield, while enhanced excitation efficiency just plays a minor role. The quantum yield enhancement is affected by both the sharp tips and contact mode of the Au nanoantenna with MoS2. Polarization of the MoS2 emission was also found to be modulated by the plasmon mode of the Au nanoantenna. These single-particle spectroscopic studies allow us to unambiguously reveal the effects of the particle morphology on plasmon enhanced PL in these nanohybrids to provide a better understanding of the plasmon–exciton interactions. [ABSTRACT FROM AUTHOR]

Seed‐mediated growth has been widely used to synthesize noble metal nanoparticles with controlled size and shape. Although it is becoming possible to directly observe the nucleation process of metal atoms at the single atom level by using transmission electron microscopy (TEM), it is challenging to control the formation and growth of seeds with only a few metal atoms in homogeneous solution systems. This work reports site‐selective formation and growth of atomic scale seeds of the Au nanoparticle in a nanospace of an organic cage molecule. We synthesized a cage molecule with amines and phenols, which were found to both capture and reduce Au(III) ions to spontaneously form the atomic scale seeds containing Au(0) in the nanospace. The growth reaction of the atomic scale seeds afforded Au nanoparticles with an average diameter of 2.0±0.2 nm, which is in good agreement with the inner diameter of the cage molecule. [ABSTRACT FROM AUTHOR]

The extinction efficiency of noble metal nanoparticles (NPs), namely gold (Au) and silver (Ag), are dependent on their size and surrounding dielectric. Exploiting the Localized Surface Plasmon Resonance (LSPR) phenomenon, the composition and structure of the NPs might be tailored to achieve a configuration that optimizes their response (sensitivity) to environmental changes. This can be done by preparing a bimetallic system, benefiting from the chemical stability of Au NPs and the higher scattering efficiency of Ag NPs. To enhance the LSPR sensing robustness, incorporating solid supports in the form of nanocomposite thin films is a suitable alternative. In this context, the NPs composed of gold (Au), silver (Ag), and their mixture in bimetallic Au-Ag NPs, were grown in a titanium dioxide (TiO2) matrix using reactive DC magnetron sputtering. Thermal treatment at different temperatures (up to 700 °C) tuned the LSPR response of the films and, consequently, their sensitivity. Notably, the bimetallic film with Au/Ag atomic ratio 1 exhibited the highest refractive index sensitivity (RIS), with a value of 181 nm/RIU, almost one order of magnitude higher than monometallic Au-TiO2. The nanostructural analysis revealed a wide NP size distribution of bimetallic NPs with an average size of 31 nm, covering about 20% of the overall surface area. These findings underscore the significant potential of bimetallic film systems, namely AuAg-TiO2, in LSPR sensing enhancement. [ABSTRACT FROM AUTHOR]

Objective Nanomedicine can play an important role in the various stages of prevention, diagnosis, treatment, vaccination, and research related to coronavirus disease 2019 (COVID-19). While nanomedicine is a powerful interdisciplinary means that offers various approaches in patient treatment, a number of factors should be critically studied to find approaches and mechanisms in the prevention, diagnosis, and treatment of this disease. This bibliometric analysis was designed to explore studies on the current knowledge of the structure, its mechanism of cell binding, and the therapeutic effect of nanomedicine on COVID-19. Materials and Methods The study data was searched from Web of Science Core Collection(WoSCC) between 2017 and 2021. Biblioshiny and VOSviewer were used to analyze and visualize patterns in scientific literature derived from WoS. Results The three clusters of keywords resulted relating to aim. Cluster 1 looking into epidemiological and public health studies on COVID-19. Cluster 2 included terms associated with virus transition, such as receptor binding, membrane glycoprotein, membrane fusion, and viral envelope proteins. Cluster 3 involved high-frequency keywords associated with nanomedicine, such as metal nanoparticles, drug delivery system doxorubicin, immunology, immune response, inflammation, and unclassified drug. Keywords such as "nanotechnology" and "gold nanoparticles" were at the center of COVID-19 related clusters, indicating the importance of these areas during the outbreak. Conclusions Understanding the advanced virology of coronaviruses and interfering with their spread through nanomedicine could significantly impact global health and economic stability. Continuous research is needed to accelerate the transfer of nanomedicine results into practice of treatment without risk of side effects. [ABSTRACT FROM AUTHOR]

The design and development of silver and gold nanoparticles incorporated into silk fibroin and gelatin composite nanofibers were prepared using the electrospun method. The functional group, chemical composition, and thermal stability of composite nanofibrous scaffolds were investigated using different characterization techniques. The confirmation of SF/GL/Ag-Au composite nanofibers was achieved through FE-SEM and AFM images, which proved to be highly beneficial for assessing surface morphology, thickness, and roughness area (Ra) with dimensions of 777 nm and 292.71 nm, respectively. Furthermore, HR-TEM images were used to elucidate the morphological structure and size of metal nanoparticles in SF/GL/Ag-Au composite nanofibers, revealing an average diameter length of 220.85 ± 82.65 nm for Ag and Au nanoparticles sizes noted at 6.25 nm and 11.56 nm. In addition, flow cytometry analysis of SF/GL/Ag-Au composite nanofibers was conducted to assess the viability of L929 cells and detect the apoptosis levels. Furthermore, invivo wound healing studies were performed on Sprague-Dawley rat animals. The results demonstrated that SF/GL/Ag-Au composite nanofiber scaffolds significantly accelerated wound closure, achieving a remarkable 99.58 % wound healing rate in the 21 days compared to control groups. In conclusion, our findings highlight that SF/GL/Ag-Au composite nanofiber scaffolds are highly suitable for wound dressing applications. [Display omitted] • The SF/GL/Ag-Au composite nanofiber was prepared through the electrospinning method. • Silk fibroin and gelatin act as reducing and stabilizing agents for metal nanoparticles. • The average diameter length of SF/GL/Ag-Au composite nanofibers is 220.85 ± 82.65 nm. • Flow cytometry analysis is more beneficial for detecting apoptosis and cell viability. • SF/GL/Ag-Au composite nanofiber is the most effective material for wound dressing applications. [ABSTRACT FROM AUTHOR]

This work presents the results of a study of the physical-chemical properties of gold nanoparticles (NP) prepared in reverse micellar solutions (RMS) using various ion reduction methods, including self-assembly (SA). The spectra of the electron plasmon resonance of the Au NP in the visible region (λmax ~ 530 nm) and in the UV region of the spectrum (λmax ~ 200–220 nm) were recorded by UV–Vis spectrophotometry. In the present work, the kinetics of the primary stages of the formation of Au NPs in RMS using various synthesis methods, including SA, has been studied. Based on the results we obtained, an explanation has been provided for the effect of oxygen (aerobic conditions) on the primary stages of the formation of Au NPs using chemical (Chem) synthesis in the presence of the flavonoid quercetin, and radiation-chemical (RadChem) one based on interaction with intermediate particles of water radiolysis. The formation of Au NPs with optical absorption bands in the UV region and the visible region of the spectrum has been corroborated by the results of electron microscopy. [ABSTRACT FROM AUTHOR]

Significant optical nonlinearities in amorphous nanocomposites are essential for developing advanced communications and photonic devices. In this regard, the borate glasses are considered substantial and readily available commercial hosts. The present work demonstrates the white light emission and decay properties in lithium bismuth boro-phosphate glasses reinforced with gold nanoparticles (AuNPs) prepared via melting and quenching technique. Also, their non-linear optical properties are evaluated in the present study. Numerous characterization methods were used to extensively examine the produced glasses, including XRD, HR-TEM, FTIR, XPS, MAS-NMR, DSC, UV–Visible, Photoluminescence, and Z-scan techniques. Following the addition of AuNPs into the glass matrix, an increase in the refractive index and density of the glasses was observed. The amorphous features of the glass sample are disclosed by XRD examination, and DSC research demonstrates the thermal stability of the glasses after the addition of AuNPs, as shown by the rise in T g values from 459 °C to 486 °C. HR-TEM results reveal the presence of Au metal nanoparticles having a cubic crystal structure with an average size of 14 nm, while XPS analysis shows that the valence of Au is 0, i.e. Au0 or, in other words, the metallic nature of gold in glasses. FTIR, MAS-NMR, and UV–Visible spectral studies demonstrate the substantial modifications in the physical, structural, and optical properties brought about by incorporating AuNPs into the glass matrix. The PL spectra of glasses containing AuNPs show three distinct, sharp emissions at 494, 611, and 738 nm, out of which the blue emission (494 nm) is found to be predominant and has an overall emission in the region of yellow on the CIE diagram with an average lifetime of 12.23 μs. Glasses containing AuNPs have a white light correlated colour temperature (CCT) of 5129 K and CIE chromaticity (x, y) coordinates of (0.346, 0.413). Additionally, we utilized a Z-scan technique to measure the nonlinear absorption coefficient and nonlinear refractive index. Our experimental data show that the values obtained are consistent with the theoretical closed and open aperture values. Based on our findings, it appears that the glasses we prepared have the potential to be utilized in optical switching applications. [ABSTRACT FROM AUTHOR]

The biomedical applications of the noble metal nanoparticles have been the field of interest, especially in cancer therapy. In this paper, the synthesis of spherical silver and gold nanoparticles and their apoptotic activity against breast cancer cells is reported. The chemicals reduction method is used to synthesize nanoparticles. Two different types of surfactants i.e., citrate and polyvinylpyrrolidone were used as a reducing and capping agent. The synthesized nanoparticles have been characterized using X-ray diffraction, ultraviolet-visible absorption spectroscopy, dynamic light scattering, zeta potential and transmission electron microscopy. The synthesized nanoparticles have crystalline phase with average size in the range of 25-30 nm and possess negative surface charge. In vitro studies of nanoparticles against breast cancer cells (MCF-7), were performed. The results show the significant cytotoxicity of nanoparticles against the cancer cell line and found to be mediated by DNA damage. [ABSTRACT FROM AUTHOR]