Gold Particles Research Articles

Investigation of heat transfer phenomenon in a complex wavy divergent channel under the effects of thermal radiation, joule heating and electroosmosis

The heat transfer analysis in electro osmotic flow of nanofluid is studied through the complex wavy channel under the consideration of joule heat and thermal radiation effects. The Ellis fluid is considered a base fluid and gold particles are suspended in them. The complex system of equations is converted to dimensionless form with the help of dimensionless transformation and parameters. The concepts of longer wavelength and lower Reynolds number are utilized to simplify the problem and obtain the exact solution of velocity and temperature distribution by using the built-in command DSolve in the mathematical software MATHEMATICA 13.3. The graphs are plotted with the same software to check the effects of various parameters on velocity, temperature, heat transfer rate, and streamlines with the following range of parameters − 5 ≤ U H S ≤ 5 , 0 ≤ β ≤ 5 , 0 ≤ α ≤ 3 , 0 < k ≤ 5 , 0 ≤ ϕ ≤ 0.04 , 20 ≤ P r ≤ 28 , 0 ≤ R n ≤ 5 . The computational results reported that the electroosmotic parameter, Helmholtz-Smoluchowski velocity, and material parameter reduce the velocity in the initial region and enhance the final region of the channel. It is also noted that the velocity profile exhibits increasing and decreasing behavior in the initial and final region respectively with upgrading the values of volumetric concentration of nanoparticles. The heat transfer rate is strongly affected by material parameters α and β , thermal radiation parameter, Prandtl number, and joule heating and these parameters promote the heat transfer rate of the system. The novel research of the current study shows the examination of the heat transfer analysis of blood-gold nanofluid in the presence of an electrical double layer and thermal radiation with the help of the Ellis nanofluid flow model through a complex symmetric wavy channel. The results of the present investigation are useful for the early detection of renal diseases and monitoring of disease progression because of the unique properties of gold nanoparticles. The role of gold nanoparticles as imaging agents, drug delivery antioxidant properties, biosensing, targeted therapy, and renal clearance makes them the perfect choice for renal diseases.

Gold Nanoparticle Virus-like Particles Presenting SARS-CoV-2 Spike Protein: Synthesis, Biophysical Properties and Immunogenicity in BALB/c Mice.

Gold nanoparticles (AuNPs) decorated with antigens have recently emerged as promising tools for vaccine development due to their innate ability to provide stability to antigens and modulate immune responses. In this study, we have engineered deactivated virus-like particles (VLPs) by precisely functionalizing gold cores with coronas comprising the full SARS-CoV-2 spike protein (S). Using BALB/c mice as a model, we investigated the immunogenicity of these S-AuNPs-VLPs. Our results demonstrate that S-AuNPs-VLPs consistently enhanced antigen-specific antibody responses compared to the S protein free in solution. This enhancement included higher binding antibody titers, higher neutralizing capacity of antibodies, and stronger T-cell responses. Compared to the mRNA COVID-19 vaccine, where the S protein is synthesized in situ, S-AuNPs-VLPs induced comparable binding and neutralizing antibody responses, but substantially superior T-cell responses. In conclusion, our study highlights the potential of conjugated AuNPs as an effective antigen-delivery system for protein-based vaccines targeting a broad spectrum of infectious diseases and other emergent viruses.

Chirality-Dependent Reprogramming of Macrophages.

The chirality of materials directly influences their transport and biological effects in physiological conditions. However, the impact of chiral materials on cellular metabolic reprogramming remains incompletely elucidated. In this study, we have synthesized chiral gold particles through a light-driven particle growth approach and demonstrated that d-Au particles exhibited superior macrophage activation ability compared to l-Au particles. An inflammatory creatine-phosphocreatine shunt was induced following d-Au stimulation. This shunt, facilitated by the upregulated expression of creatine kinase muscle-type (CKM), also resulted in a reduction in cytosolic levels of creatine. Pharmacological inhibition and genetic ablation of CKM further suppressed the secretion of pro-inflammatory cytokines, without compromising mitochondrial respiration. Moreover, the activation of macrophages induced by d-Au was mediated through the activation of the NF-κB and NLRP3 inflammasome pathways. Inhibition of CKM expression not only decreased the secretion of CXCL2 but also attenuated IL-1β by suppressing the NLRP3 inflammasome pathways. Our investigation into the metabolic reprogramming mechanism of chiral materials on macrophage activation is pivotal for the application of chiral-based anticancer therapies.

Spherical nucleic acid nanoprobes for in situ and multiplex detection of exosomal PIWI-interacting RNAs

PIWI-interacting RNAs (piRNAs) are a novel class of non-coding RNAs that bind specifically to the PIWI subfamily of Argonaut proteins. It has been increasingly demonstrated that piRNAs encased in circulating exosomes could be an ample source of potential tumor markers for cancer diagnostics. However, methods on exosomal piRNAs detections are limited, and most of them need extraction of piRNAs from the sample which is laborious and disadvantage to clinical applications. Herein, we developed two kinds of dual-targeted spherical nucleic acid nanoprobes for in situ and multiplex detection of exosomal piRNAs. The detection scheme was rationally designed for the large sized targets of PIWI-interacting RNA complex which could generate steric hindrance in the detection reaction. The probes were synthesized by modifying 13-nm gold particles with high-density double stranded anchor-report DNA through butanol dehydration method. The key synthesis condition of molar ratio between the two kinds of anchor-report DNA chains were optimized for preparing probes with good structural reproducibility. The probes can perform in situ and multiplex detection of piRNAs in exosomes after simple incubation. In the clinical assays of plasma from breast cancer patients and normal control groups, the probes can differentiate the expression levels of 3 types of piRNAs and their combinations in high specificity and sensitivity. These new piRNA probes are potentially to perform simple and accurate liquid biopsy for cancer diagnostics.

Monodispersed mesoscopic star-shaped gold particles via silver-ion-assisted multi-directional growth for highly sensitive SERS-active substrates

Surface-enhanced Raman scattering (SERS) exploits localized surface plasmon resonances in metallic nanostructures to significantly amplify Raman signals and perform ultrasensitive analyses. A critical factor for SERS-based analysis systems is the formation of numerous electromagnetic hot spots within the nanostructures, which represent regions with highly concentrated fields emerging from excited localized surface plasmons. These intense hotspot fields can amplify the Raman signal by several orders of magnitude, facilitating analyte detection at extremely low concentrations and highly sensitive molecular identification at the single-nanoparticle level. In this study, mesoscopic star-shaped gold particles (gold mesostars) were synthesized using a three-step seed-mediated growth approach coupled with the addition of silver ions. Our study confirms the successful synthesis of gold mesostars with numerous sharp tips via the multi-directional growth effect induced by the underpotential deposition of silver adatoms (AgUPD) onto the gold surfaces. The AgUPD process affects the nanocrystal growth kinetics of the noble metal and its morphological evolution, thereby leading to intricate nanostructures with high-index facets and protruding tips or branches. Mesoscopic gold particles with a distinctive star-like morphology featuring multiple sharp projections from the central core were synthesized by exploiting this phenomenon. Sharp tips of the gold mesostars facilitate intense localized electromagnetic fields, which result in strong SERS enhancements at the single-particle level. Electromagnetic fields can be further enhanced by interparticle hot spots in addition to the intraparticle local field enhancements when arranged in multilayered arrays on substrates, rendering these arrays as highly efficient SERS-active substrates with improved sensitivity. Evaluation using Raman-tagged analytes revealed a higher SERS signal intensity compared to that of individual mesostars because of interparticle hot spots enhancements. These substrates enabled analyte detection at a concentration of 10− 9 M, demonstrating their remarkable sensitivity for trace analysis applications.

P-035 Catecholamine neuroreceptors are differentially located in functional regions of the human sperm

Abstract Study question How are the expression and distribution of Adrenergic and Dopamine receptors in human sperm cells? Summary answer Using ultra-high-resolution microscopy techniques, we identified that each type of catecholamine receptor is expressed in a different functional region of the human sperm. What is known already Human sperm present complex cell signalling complexes with several neuroreceptors in their membrane. The spermatozoa is a terminal differentiated cell showing specialized regions optimized for physiological processes like motility, acrosome reaction and membrane fusion during fertilization. Although indirect methods have determined the presence of catecholamine receptors in human sperm, there is no direct evidence nor description of the exact localisation of these receptors. Catecholamine receptors are the direct target of medications used to treat very frequent health problems like hypertension (beta blockers), asthma (bronchodilators) and mental health disorders (antipsychotics and antidepressants). Study design, size, duration We design the study by developing new techniques that allow us to use high-resolution microscopes (i.e. Laser Scanning Confocal Microscopy LSCM and Field Emission Scanning Electron Microscopy or FE-SEM) to identify the localisation and distribution of catecholamine receptors. We determined sperm functional regions and quantified the relative amount of the different receptors on each one of those regions to perform a statistical analysis. Participants/materials, setting, methods After informed consent and ethical approval, sperm from young, healthy donors (n = 20) were included in the study. We used the neuroblastoma cell line SH-SY5Y as a positive control. Immunolabelling techniques used specific primary antibodies for each receptor, followed by the gold-conjugated secondary antibodies for FE-SEM. Negative controls were performed by omitting the primary antibody. In FE-SEM images, we quantify the number of gold nanoparticles in the sperm cells and the background. Main results and the role of chance We confirm the differential localisation of the different receptors studied. Dopamine D2 receptors are mainly expressed on the equatorial band of the acrosome, while beta-adrenergic receptors are restricted to the terminal piece of the flagellum. In both cases, the mean number of gold particles showed statistical differences (p &amp;lt; 0,001) between the region of expression and the rest of the regions and the background. Limitations, reasons for caution The present study only shows the presence of the receptors on the sperm plasma membrane. The activity of those receptors should be investigated by developing bioassays based on the use of agonists and/or antagonists. A more reliable genetic overexpression or knockout approach was impossible in human sperm. Wider implications of the findings The presence of receptors on restricted regions of the sperm suggests their participation in critical physiological events, like regulation of sperm motility hyperactivation or acrosome reaction. It may also suggest a possible side effect of beta-blockers or bronchodilators with the male fertility potential that needs to be investigated. Trial registration number not applicable

Oxygen-Terminated Polycrystalline Boron-Doped Diamond Superhydrophobic Surface with Excellent Mechanical and Thermal Stabilities.

Superhydrophobic surfaces are of great interest because of their remarkable properties. Due to its maximal hardness and chemical inertness, diamond film has great potential in fabricating robust superhydrophobic surfaces. In the present study, an oxygen-terminated polycrystalline boron-doped diamond (O-PBDD) superhydrophobic surface with micro/nano-hierarchical porous structures is developed. The preparation method is very simple, requiring only sputtering and dewetting procedures. The former involves sputtering gold and copper particles onto the hydrogen-terminated polycrystalline boron-doped diamond (H-PBDD) to form gold/copper films, whereas the latter involves placing the samples in an atmospheric tube furnace to form hierarchical pores. By controlling the etching parameters, the wettability of the O-PBDD surface can be adjusted from hydrophilic to superhydrophobic, which is significantly different to the normal hydrophilicity feature of O-termination diamonds. The water contact angle of the obtained O-PBDD surface can reach 165 ± 5°, which is higher than the superhydrophobic diamond surfaces that are reported in the literature. In addition, the O-PBDD surface exhibits excellent durability; it can maintain satisfactory superhydrophobicity even after high-pressure, high-temperature, and sandpaper friction tests. This work provides a new research direction for fabricating robust superhydrophobic materials with diamond film.

Development of a flow reactor incorporating polydopamine-poly(ε-caprolactone) with gold particles

Addressing the significant challenge of dye wastewater pollution, this study introduces a novel solution employing a flow catalytic reactor loaded with gold (Au) particles. The reactor utilizes a porous monolithic material with a Poly(ε-caprolactone) (PCL) matrix as the carrier for Au particles, with polydopamine employed to immobilize the Au onto the surface of the PCL monolith. To assess the catalytic efficiency of the reactor, a model catalytic degradation experiment involving the reaction between methyl orange (MO) and sodium borohydride was conducted. The catalytic reaction was facilitated by a peristaltic pump. The reactor setup involved fixing the monolith within a heat shrinkable tube, and the peristaltic pump ensured the flow catalytic reaction. The protective effect of liquid nitrogen was utilized to confirm that the porous structure of the PCL monolith, with its low melting point, remained intact after being fixed in the heat shrink tube. Catalytic results revealed remarkable efficacy, with the decomposition efficiency of MO reaching 98.54%. This flow reactor enables continuous operation, making it more practical for real-world applications compared to traditional batch methods. Furthermore, even after 5 cycles, the sample maintained a catalytic efficiency exceeding 90%, demonstrating the excellent reusability of the reactor.

Synergistic Exploration of Heat Transfer for Integration Magnetohydrodynamics of Nanofluids Peristaltic Transport within Annular Tubes

The problem of treating cancer is considered one of the most important daily challenges that affect the lives of people with cancer. This research deals with solving this problem theoretically. Through previous studies, it has been proven that gold nanoparticles are able to remove these cancer cells. The idea of this research is theoretically based on injecting a cancer patient with gold nanoparticles that are exposed to a magnetic field. When these particles penetrate cancerous cells and are exposed to a magnetic field, this causes their temperature to rise. The high temperature of the nanometer gold particles that penetrate the cells of the affected body leads to the explosion of the cancer cells. In this research, the various external forces that affect the flow movement of the nanofluid are studied and how its physical and thermal properties are affected by those external forces. The MHD peristaltic flow of a nanofluid in an annulus pipe as a result of the effect of the wall properties has been investigated. This has been achieved through slip and thermal conditions. Wave velocity leads to flow development. The inner annulus wall is rigid, while the outer wall of the artery moves under the influence of wave peristaltic movement. The nonlinear equations that describe the flow are solved under long-wavelength assumptions. The results were compared with other numerical methods, such as finite volume and finite element and the long wavelength method and proved to be accurate and effective. The expressions of pressure difference, velocity, stream function, wall shear stress, and temperature are analyzed. It is noted that the flow velocity increases with the Knudsen number, and the increased source heat suggests an increased temperature. The increasing amplitude ratio at most of the interface points between the artery wall and the catheter results in increased velocity. The streamlines are affected by the magnetic field, as increasing the influencing magnetic field leads to a decrease in flow lines. It is observed that this stress decreases when nanoparticles increase, in contrast to the effect of the magnetic field and also the occurrence of slipping. It was found that the mass of the wall cells relative to their area works to decrease the pressure difference, in contrast to the tension between those cells, which works to increase the pressure difference. Without slipping and with slipping , the temperature decreases with increasing in nanoparticle concentration . The temperature also increases with the amplitude ratio . This strongly affects the generated drag on the catheter wall, which is mainly responsible for the enhanced temperature on this wall.

Numerical investigation of Casson fluid flow performance of blood containing gold and Fe3O4 nanofluid injected into a stenotic artery

The study of the movement of blood across a stenotic artery is an important one in the discipline of mathematical fluid mechanics because of the importance it has in the field of biomedical research. The current study’s primary objective is to learn how nanoparticles influence blood flow through a narrowed artery. Within an examination of the theoretical flow situation, we investigate the importance of Casson nanofluid flow across a heart artery. Similarity transformations aid in the conversion of the partial differential equations into ordinary differential equations. After that, the non-dimensional equations are solved by using the MATLAB software in the Bvp5c technique. Enhancing the magnetic characteristics of the blood stream tissues was explored by boosting the magnetic field parameter, leading to a decrease in blood circulation as expected. At higher values of the Casson fluid parameter, the velocity profile decreased. Increasing the concentration of gold particles in the narrowed artery makes it more efficient at transferring heat. The use of iron nanoparticles in medicine delivery is supported by an argument. The method that is currently being used may be of assistance in dispersing pharmaceuticals across the blood stream. We employ a visual representation to facilitate the presentation of this drug delivery mechanism’s theoretical outcomes.

Efficient formation of propylene oxide under low hydrogen concentration in propylene epoxidation over Au nanoparticles supported on V-doped TS-1

The direct epoxidation of propylene to propylene oxide (PO) represents a unique feature of gold nanoparticle catalysts. Different amounts of vanadium were introduced into TS-1 using a hydrothermal method to give V-TS-1, and the effect of various vanadium loadings on the catalytic performance of Au/V-TS-1 was investigated in the epoxidation of propylene under different reaction conditions. The obtained characterization results indicate that the molecular sieve pore structure and crystalline phase structure of TS-1 were maintained after vanadium incorporation, and vanadium was incorporated into the molecular sieve framework. The introduction of an appropriate amount of vanadium resulted in the homogeneous dispersion of gold particles with a small average particle size, which facilitated the epoxidation reaction. When V was introduced into TS-1, the propylene conversion decreased under the condition of 10 % H2 concentration (C3H6/H2 = 1/1) in the reaction atmosphere, but the PO selectivity was maintained. Interestingly, when the H2 concentration in the reaction atmosphere was lowered to 2 % (C3H6/H2 = 3/1), the propylene conversion in Au/TS-1 was significantly decreased compared to 10 % H2 concentration condition, while in Au/V-TS-1, the propylene conversion was maintained in 2 % H2 concentration condition compared to 10 % H2. Au/V-TS-1 also maintained its selectivity for PO even when the H2 concentration was lowered. Therefore, under low hydrogen concentration conditions, the PO formation rate of Au/V-TS-1 was much higher than that of Au/TS-1. More, the same trend was observed when Mo was added in place of V. Our strategy will guide the design of future catalysts as a way to utilize hydrogen more effectively while maintaining PO productivity.

Ceramic conversion treated titanium implant abutments with gold for enhanced antimicrobial activity

IntroductionPeri-implantitis is an inflammatory process around dental implants that is characterised by bone loss that may jeopardize the long-term survival of osseo integrated dental implants. The aim of this study was to create a surface coating on titanium abutments that possesses cellular adhesion and anti-microbial properties as a post-implant placement strategy for patients at risk of peri-implantitis. Materials and MethodsmethodsTitanium alloy Grade V stubs were coated with gold particles and then subjected to ceramic conversion treatment (CCT) at 620 °C for 3, 8 and 80 h. The surface characteristics and chemistry were assessed using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD) analysis. The leaching profile was investigated by inductively coupled plasma mass spectroscopy (ICP-MS) for all groups after 7, 14 and 28 days in contact with distilled water. A scratch test was conducted to assess the adhesion of the gold coating to the underlying titanium discs. Two bacterial species (Staphylococcus aureus (SA) &Fusobacterium nucleatum (FN)) were used to assess the antibacterial behaviour of the coated discs using a direct attachment assay test. The potential changes in surface chemistry by the bacterial species were investigated by grazing angle XRD. ResultsThe gold pre-coated titanium discs exhibited good stability of the coating especially after immersion in distilled water and after bacterial colonisation as evident by XRD analysis. Good surface adhesion of the coating was demonstrated for gold treated discs after scratch test analysis, especially titanium, following a 3-hour (3 H) ceramic conversion treatment. All coated discs exhibited significantly improved antimicrobial properties against both tested bacterial species compared to untreated titanium discs. ConclusionsCeramic conversion treated titanium with a pre-deposited gold layer showed improved antimicrobial properties against both SA and FN species than untreated Ti-C discs. Scratch test analysis showed good adherence properties of the coated discs the oxide layer formed is firmly adherent to the underlying titanium substrate, suggesting that this approach may have clinical efficacy for coating implant abutments.

Synthesis of Anisotropic Gold Microparticles via L‐Glutathione‐Mediated Pathways in Droplet Microfluidics

AbstractMicrofluidic‐assisted synthesis of nanoparticles has generated significant interest for its precise control and high throughput capabilities. Among various nanomaterials, gold nanoparticles (AuNPs) have shown remarkable potential in numerous applications, such as disease detection, photothermotherapy, drug delivery, and even defense applications. Recent synthesis strategy of peptide‐mediated method has sparked greater interest by offering unique chiroptical properties and their applications in biomedical applications. In this study, the use of droplet microfluidics is explored for the synthesis of peptide‐mediated AuNPs, aiming to accelerate automated production via flow chemistry. This method leads to the formation of anisotropic gold particles, with sizes ranging from hundreds of nanometers to the micron scale. The interfacial energy is identified at the water/oil interface as a critical factor influencing this outcome, with L‐glutathione (L‐GSH) playing a significant role in the development of hyper‐branched structures. These results demonstrate the capability of droplet microfluidics in producing anisotropic gold particles at micron scales, presenting new possibilities for the advancement of nanoparticle synthesis techniques.

Carcinoembryonic antigen and cancer antigen 125 simultaneously determined using a fluidics-integrated dual carbon electrode

Carcinoembryonic antigen (CEA) and cancer antigen 125 (CA125) are important tumor markers for the diagnosis of ovarian cancer at the metastasis stage. Here, CEA and CA125 were simultaneously detected by a label-free electrochemical immunosensor. Using a stencil and carbon ink, a dual carbon electrode (DCE) was fabricated on a poly(vinyl chloride) substrate. Gold particles (AuPs) were electrodeposited on the electrode as a signal amplifier and support for immobilized antibodies. Linear sweep voltammetry was utilized to detect the tumor markers based on the specific binding of antigens to antibodies. Scanning electron microscopy and atomic force microscopy were used to characterize the fabricated DCE. The results were compared to those of a commercial DCE. Using the developed DCE immunosensor, we achieved a linear range of CEA from 0.5 to 25 ng mL−1 and a linear range of CA125 from 2 to 50 U mL−1. The limits of detection of CEA and CA125 were 0.15 ng mL−1 and 0.6 U mL−1, respectively. The reliability of the immunosensor was evaluated using human serum. The results were consistent with those obtained from the reference enzyme-linked fluorescence assay. The immunosensor was integrated with a small plasma membrane to form a fluidic cell (Flu-iDCE) based on acrylic sheet. The membrane had no effect on the detection of the tumor markers with the proposed Flu-iDCE. This first report of a fluidic device integrated with a DCE demonstrates the potential of the device for point-of-care detection of CEA and CA125.

Enhancing ICF Target Design: The Impact of Gold Particles as Pusher on Ignition and Burn

Enhancing ICF Target Design: The Impact of Gold Particles as Pusher on Ignition and Burn

A highly specific and ultrasensitive approach to detect Prymnesium parvum based on RPA-CRISPR-LbaCas12a-LFD system

BackgroundHarmful algal blooms (HABs), caused by the rapid proliferation or aggregation of microorganisms, are catastrophic for the environment. The Prymnesium parvum is a haptophyte algal species that is found worldwide and is responsible for extensive blooms and death of larval amphibians and bivalves, causing serious negative impacts on the ecological environment. For the prevention and management of environmental pollution, it is crucial to explore and develop early detection strategies for HABs on-site using simple methods. The major challenge related to early detection is the accurate and sensitive detection of algae present in low abundance. ResultsHerein, recombinase polymerase amplification (RPA) was combined with clustered regularly interspaced short palindromic repeats and Cas12a protein (CRISPR-LbaCas12a) systems, and the lateral flow dipstick (LFD) was used for the first time for early detection of P. parvum. The internal transcribed spacer (ITS) of P. parvum was selected as the target sequence, and the concentration of single-strand DNA reporters, buffer liquid system, reaction time, and amount of gold particles were optimized. The RPA-CRISPR-LbaCas12a-LFD approach demonstrated highly specificity during experimental testing, with no cross-reaction against different microalgae used as controls. In addition, the lowest detection limit was 10,000 times better than the lowest detection limit of the standalone RPA approach. The feasibility and robustness of this approach were further verified by using the different environmental samples. It also observed that P. parvum are widely distributed in Chinese Sea, but the cell density of P. parvum is relatively low (<0.1 cells/mL). SignificanceThe developed approach has an excellent specificity and offers 10,000 times better sensitivity than the standalone RPA approach. These advantages make this approach suitable for early warning detection and prevention of HAB events in environmental water. Also, the outcomes of this study could promote a shift from traditional laboratory-based detection to on-site monitoring, facilitating early warning against HABs.

In Situ Surface-Enhanced Raman Spectroscopy on Organic Mixed Ionic-Electronic Conductors: Tracking Dynamic Doping in Light-Emitting Electrochemical Cells.

In the domain of organic mixed ionic-electronic conductors (OMIECs), simultaneous transport and coupling of ionic and electronic charges are crucial for the function of electrochemical devices in organic electronics. Understanding conduction mechanisms and chemical reactions in operational devices is pivotal for performance enhancement and is necessary for the informed and systematic development of more promising materials. Surface-enhanced Raman spectroscopy (SERS) is a potent tool for monitoring electrochemical evolution and dynamic doping in operational devices, offering enhanced sensitivity to subtle spectral changes. We demonstrate the utility of SERS for in situ tracking of doping in OMIECs in an organic light-emitting electrochemical cell (LEC) containing a conjugated polymer (poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene]; MEH-PPV), a molecular anion (lithium triflate), and an electrolyte network (poly(ethylene oxide); PEO). SERS enhancement is achieved via an interleaved layer of gold particles formed by spontaneous breakup of a deposited thin gold film. The results successfully highlight the ability of SERS to unveil time-resolved MEH-PPV doping and polaron formation, elucidating the effects of triflate ion transfer in the operating device and validating the electrochemical doping model in LECs.

Effects of Multispectral Absorbing Coating on the Generated Voltage of Solar Radiation–Thermoelectric System

The effective utilization of solar energy is an important development direction to realize the exploration of clean energy. Herein, a model of solar radiation–thermoelectric generation (TEG) system is established, which is composed of solar absorbing coating and TEG component. Five different microscopic structures of coating are designed and the spectral absorption properties are numerically analyzed with the finite‐difference time‐domain method. Then, the absorbed solar energy and produced open‐circuit voltage with different coating structures are compared, with the coupling calculation of temperature field and electromagnetic field achieved. Additionally, the effects of structural size parameters on the output voltage performance are discussed. It can be observed that the absorbing coating can effectively improve the performance of TEG component, and the multilayer structure with appropriate gold particle diameter chosen is an optimization research direction for more efficient energy conversion.

Morphostructural, Chemical and Genetic Features of Native Gold in Brown Coals from the Yerkovetsky Deposit, Far East Russia

We studied the morphostructural features and chemical composition of micron and submicron particles of native gold from brown coals and overcoal sediments of the Yerkovetsky deposit (Zeya-Bureya sedimentary basin, Far East Russia). The samples of coal and host rocks in the form of thin sections, as well as coal particles and grains of native gold obtained during the process of dispersion and the fractionation of loose and crushed samples divided according to size and density, were analyzed using scanning electron microscopy in combination with X-ray microanalysis, involving various visualization modes. It was revealed that native gold is syngenetic with the mineralization of brown coals, and microphases dispersed in the minerals of overcoal loose and sandy-clay sediments were the source of native gold. In coal, gold is accumulated at the stages of formation (alluvial and eolian, including terrigenous and ionogenic subtypes) and the diagenesis of coal deposits (ground-infiltration subtype). A significant part of the mineralization process of coals and the formation of microparticles of native gold was contributed to by the descending water infiltration of polycomponent colloid solutions. During the dehydration of hydroxysiliconized iron-based hydrogels, mineral phases have an unstable composition and floccular structure and contain submicron gold particles. The coatings of all gold microparticles have identical origin and composition. Coal beds that border host rocks are an open system with a constant inflow of the substance, which leads to the gradual formation of polycomponent aggregated particles in micro cavities. Part of the gold in coals occurs as sulfur-bearing complexes dissolved in pore water. The key factor in the migration and deposition of gold in coals is the inorganic substances involved in the processes of coal mineralization. Organic substances play a more passive role and have medium-forming, fractionating (colloid, molecular, and ionic sieves), and accumulation functions.

Near-infrared radiation of gold–platinum submicron particle-decorated nonwoven mats enhances wound healing: In vitro and In vivo studies

Because of their biocompatibility and unique optical and electrical properties, Pt nanoparticles (NPs) have been extensively utilized in biomedical applications. However, the use of pure Pt NPs is hindered by the high costs of raw material and absorption at ultraviolet wavelengths. To leverage the benefits of Pt particles while mitigating their drawbacks, we applied electrospinning technology to prepare polyacrylonitrile (PAN) nonwoven mats decorated with gold and platinum submicron particles (Au5Pt3 submicron particle-decorated PAN). We examined the surface morphology, elemental composition, and chemical structure of the resultant Au5Pt3-decorated PAN nonwoven mats by field emission scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, and EDX elemental mapping. When subjected to near-infrared (NIR) illumination, the Au5Pt3-decorated PAN nonwoven mats showed a more stable temperature rise than pure PAN nonwoven mats or Au PAN nonwoven mats. Inductively coupled plasma spectrometry demonstrated that the Au5Pt3-decorated PAN nonwoven mats can release more Pt ions under NIR illumination, reaching concentrations of up to approximately 8 ppm. The Au5Pt3-decorated PAN nonwoven mats exerted positive effects in a wounded mouse model, with or without NIR irradiation: the films did not cause wound adhesion or fibrosis, and excellent skin tissue healing and collagen regeneration were observed. Moreover, when combined with NIR illumination, the Au5Pt3 submicron particle-decorated PAN nonwoven mats more strongly inhibited the growth of Gram-positive and Gram-negative bacteria and more strongly enhanced blood vessel generation, compared with the same mats in the absence of NIR illumination. Regardless of NIR irradiation, the Au5Pt3 submicron particle-decorated PAN nonwoven mats do not show significant damage to the liver or kidney in mice. Overall, treatment with these Au5Pt3 submicron particle-decorated PAN nonwoven mats does not result in toxicity in mice and exerts a positive effect on wound healing when combined with NIR irradiation, with enhanced angiogenesis and collagen regeneration.