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One of the most promising approaches to addressing the current global energy and environmental crisis is the development and utilization of hydrogen energy. Photoelectrochemical (PEC) water splitting represents a clean and sustainable method for converting solar energy into hydrogen. In this article, we employed a hydrothermal-photodeposition method to fabricate Au@Pt decorated polyaniline (PANI)/TiO 2 (TNAP), which realized the synergy of p-n heterojunction and surface plasmon resonance (SPR). Experimental results revealed that p-n heterojunction can be formed between PANI and TiO 2 , whereas PANI can utilize visible light and the strong interaction between Au and PANI can realize the rapid transfer of hot electrons. Meanwhile, the outer layer Pt nanoparticles can accelerate water oxidation reaction kinetics. Therefore, the as-prepared TNAP exhibited the synergy promotion of p-n heterojunction and SPR effect, which is benefit for promoted light utilization and efficient charge transfer and separation. The optimized TNAP structure achieved hydrogen evolution rate of 19.26 μmol/cm2·h and photocurrent density of 1.20 mA/cm2 at a bias of 1.23 V vs. RHE, which is significantly higher than that of single semiconductor. This article suggests that the synergy promotion of SPR effect and p-n heterojunction is an efficient strategy to promote the efficiency of PEC water splitting. [Display omitted] • PANI/TiO 2 p-n heterojunction realizes the spatial separation of charge carriers. • Au NPs induced strong SPR effect and improve light utilization efficiency. • Strong interaction between PANI and Au promotes the transfer of hot electrons. • Surface Pt act as active sites and accelerate water oxidation reaction. • TNAP exhibited the synergy promotion of p-n heterojunction and SPR effect. [ABSTRACT FROM AUTHOR]

Optical sensors face challenges when detecting ultralow amounts of analytes in whole blood, including signal quenching due to optical absorption and false positives due to nonspecific binding. This study introduces gold nanoscale array features termed nanoledges (NLs), which interact with incident white light to produce a transmitted surface plasmon resonance (tSPR) signal. This extraordinary optical transmission (EOT) spectrum occurs in the near-infrared (NIR) region, thereby minimizing signal quenching caused by visible-light absorption from blood proteins and pigments. To develop a sensitive, selective, and label-free optical biosensor for detecting various levels of cardiac troponin I (cTnI) in very small volumes of whole blood samples, DNA aptamers are tethered to the NL surface, specifically binding to the cTnI biomarker. This biological binding activity alters the refractive index at the NL surface, causing a peak shift in the EOT spectrum and enabling quantification of cTnI levels. The NL array chip demonstrated high sensitivity for cTnI detection in buffer, human serum (HS), and human whole blood (HB), with detection limits of 0.079, 0.084, and 0.097 ng/mL, respectively. Control measurements using blank target mediums and those containing up to 125 ng/mL of other proteins, such as myoglobin, creatine kinase, and heparin, showed minimal interference and high specificity. The NL plasmonic array's performance in biosensing underscores its promise for clinical analysis and its potential development as a point-of-care platform for early cardiovascular disease (CVD) diagnostics. [ABSTRACT FROM AUTHOR]

The debate surrounding the roles of thermal and non-thermal pathways in plasmonic catalysis has captured the attention of researchers and sparked vibrant discussions within the scientific community. In this review, we embark on a thorough exploration of this intriguing discourse, starting from fundamental principles and culminating in a detailed understanding of the divergent viewpoints. We probe into the core of the debate by elucidating the behavior of excited charge carriers in illuminated plasmonic nanostructures, which serves as the foundation for the two opposing schools of thought. We present the key arguments and evidence put forth by proponents of both the non-thermal and thermal pathways, providing a perspective on their respective positions. Beyond the theoretical divide, we discussed the evolving methodologies used to unravel these mechanisms. We discuss the use of Arrhenius equations and their variations, shedding light on the ensuing debates about their applicability. Our review emphasizes the significance of localized surface plasmon resonance (LSPR), investigating its role in collective charge oscillations and the decay dynamics that influence catalytic processes. We also talked about the nuances of activation energy, exploring its relationship with the nonlinearity of temperature and light intensity dependence on reaction rates. Additionally, we address the intricacies of catalyst surface temperature measurements and their implications in understanding light-triggered reaction dynamics. The review further discusses wavelength-dependent reaction rates, kinetic isotope effects, and competitive electron transfer reactions, offering an all-inclusive view of the field. This review not only maps the current landscape of plasmonic photocatalysis but also facilitates future explorations and innovations to unlock the full potential of plasmon-mediated catalysis, where synergistic approaches could lead to different vistas in chemical transformations. The authors present a comprehensive review exploring the mechanistic understanding of plasmonic photocatalysis through examining the evidence for and interplay of thermal and non-thermal effects in this broad class of reactions. [ABSTRACT FROM AUTHOR]

Pancreatic cancer is one of the deadliest cancers worldwide, mainly due to late diagnosis. Therefore, there is an urgent need for novel diagnostic approaches to identify the disease as early as possible. We have developed a diagnostic assay for pancreatic cancer based on the detection of naturally occurring tumor associated autoantibodies against Mucin‐1 (MUC1) using engineered glycopeptides on nanoparticle probes. We used a structure‐guided approach to develop unnatural glycopeptides as model antigens for tumor‐associated MUC1. We designed a collection of 13 glycopeptides to bind either SM3 or 5E5, two monoclonal antibodies with distinct epitopes known to recognize tumor associated MUC1. Glycopeptide binding to SM3 or 5E5 was confirmed by surface plasmon resonance and rationalized by molecular dynamics simulations. These model antigens were conjugated to gold nanoparticles and used in a dot‐blot assay to detect autoantibodies in serum samples from pancreatic cancer patients and healthy volunteers. Nanoparticle probes with glycopeptides displaying the SM3 epitope did not have diagnostic potential. Instead, nanoparticle probes displaying glycopeptides with high affinity for 5E5 could discriminate between cancer patients and healthy controls. Remarkably, the best‐discriminating probes show significantly better true and false positive rates than the current clinical biomarkers CA19‐9 and carcinoembryonic antigen (CEA). [ABSTRACT FROM AUTHOR]

Following a new approach, we prepared a nanoink with two separate photothermally responsive absorption bands. One is the localized surface plasmon resonance (LSPR) absorption of gold nanoparticles (AuNP, d=17 nm), the second is the absorption band of two cyanine (Cy) dyes, Cy7‐C6 or Cy7‐C11, grafted to the AuNP surface through thiolated bridges of different lengths: the close proximity to the Au surface induces full quenching of the Cy fluorescence, resulting in thermal relaxation on irradiation. Attempts to full coat AuNP with the lipophilic Cy7‐C6 and Cy7‐C11 lead to precipitation from aqueous solutions. We thus prepared AuNP with partial pegylation (30, 50, or 70 %), using a long chain thiol‐terminated PEG bearing a ‐COOH function. Addition until saturation of either Cy7‐C6 or Cy7‐C11 to the partially pegylated AuNP gave the AuNP@Cy/PEGX% hybrids (X=30, 50, 70) that are stable in water and in the water/alcohol mixtures used to prepare the nanoinks. Further overcoating of AuNP@Cy7‐C6/PEG50 % with PAH (polyallylamine hydrochloride) avoids LSPR hybridization in the dry nanoink printouts, that present two separate bands. When irradiated with laser sources near their absorption maxima, the printouts of the AuNP@Cy7‐C6/PEG50 %@PAH nanoink respond on two channels, giving different temperature increases depending on the irradiation wavelengths. This enhances the potentiality of use of these nanoinks for photothermal anticounterfait printouts, making more difficult to reproduce the correct ΔT vs λirradiation output. [ABSTRACT FROM AUTHOR]

Photothermal catalysis effectively increases catalytic activity by using the photothermal effect of metal nanomaterials; however, the combination of strong light absorption and high catalytic performance remains a challenge. Here, we demonstrate hexagonal ~5-nanometer-thick palladium antimony (chemical formula as Pd8Sb3) nanosheets (NSs) that exhibit strong light absorption within full spectral and localized surface plasmon resonance (LSPR) effects in the visible region. Such LSPR features lead to strong photothermal effects, and Pd8Sb3 NSs aqueous dispersion enables enhanced photothermal methane (CH4) conversion to formaldehyde (HCHO) under full-spectrum light irradiation at 1.7 watts per square centimeter, leading to selectivity of ~98.7%, productivity of ~665 millimoles per gram of catalyst, ~700 times higher than that of Pd NSs. Mechanism investigations suggest that different radicals were generated on Pd8Sb3 (·OH) and Pd NSs (·O2-), where Pd8Sb3 NSs displays stronger adsorption strength to CH4 and facilitates CH4 oxidation to HCHO. Besides, the strong light absorption ability of Pd8Sb3 NSs enables photothermal therapy for breast cancer. [ABSTRACT FROM AUTHOR]

The inward rectifier potassium channel Kir2.1 (KCNJ2) is an important regulator of resting membrane potential in both excitable and non-excitable cells. The functions of Kir2.1 channels are dependent on their lipid environment, including the availability of PI(4,5)P2, secondary anionic lipids, cholesterol and long-chain fatty acids acyl coenzyme A (LC-CoA). Endocannabinoids are a class of lipids that are naturally expressed in a variety of cells, including cardiac, neuronal, and immune cells. While these lipids are identified as ligands for cannabinoid receptors there is a growing body of evidence that they can directly regulate the function of numerous ion channels independently of CBRs. Here we examine the effects of a panel of endocannabinoids on Kir2.1 function and demonstrate that a subset of endocannabinoids can alter Kir2.1 conductance to varying degrees independently of CBRs. Using computational and Surface plasmon resonance analysis, endocannabinoid regulation of Kir2.1 channels appears to be the result of altered membrane properties, rather than through direct protein-lipid interactions. Furthermore, differences in endocannabinoid effects on Kir4.1 and Kir7.1 channels, indicating that endocannabinoid regulation is not conserved among Kir family members. These findings may have broader implications on the function of cardiac, neuronal and/or immune cells. [ABSTRACT FROM AUTHOR]

Introduction: Monoclonal antibodies (mAbs) play a pivotal role in disease diagnosis as well as immunotherapy interventions. Traditional monoclonal antibody generation relies on animal immunization procedures predominantly involving mice; however, recent advances in in-vitro expression methodologies have enabled large-scale production suitable for both industrial applications as well as scientific investigations. Methods: In this study, two mAbs against H7 subtype avian influenza viruses (AIV) were sequenced and analyzed, and the DNA sequences encoding heavy chain (HC) and light chain (LC) were obtained and cloned into pCHO-1.0 expression vector. Then, the HC and LC expression plasmids were transfected into CHO-S cells to establish stable cell lines expressing these mAbs using a two-phase selection scheme with different concentrations of methotrexate and puromycin. Recombinant antibodies were purified from the cell culture medium, and their potential applications were evaluated using hemagglutination inhibition (HI), western blotting (WB), confocal microscopy, and enzyme-linked immunosorbent assay (ELISA). Results: The results indicated that the obtained recombinant antibodies exhibited biological activity similar to that of the parent antibodies derived from ascites and could be used as a replacement for animal-derived mAbs. A kinetic analysis of the two antibodies to the AIV HA protein, conducted using surface plasmon resonance (SPR), showed concordance between the recombinant and parental antibodies. Discussion: The data presented in this study suggest that the described antibody production protocol could avoid the use of experimental animals and better conform to animal welfare regulations, and provides a basis for further research and development of mAbs-based diagnostic products. [ABSTRACT FROM AUTHOR]

Strong coupling between surface plasmon resonance (SPR) modes and excitons holds great potential for many chemical and physical applications. However, a clear understanding on how far‐field spectral characteristics of SPR (linewidths and intensity) affect the coupling strength remains unclear because these parameters are difficult to be individually tuned. These spectral characteristics are associated with the damping rate and field enhancement that depend on the morphology of the plasmonic nanostructure. In this work, the influence of the SPR line shape on exciton‐plasmon coupling is systematically investigated by delicately tuning the linewidths and resonance intensities of the plasmonic arrays. It is found that the SPR modes with narrow linewidths or large intensity are favorable for the exciton–plasmon system to achieve strong coupling. The obtained clear relationships between the SPR line shape and coupling strength provide guidance for the design and optimization of exciton‐plasmon coupling systems, favoring the highly efficient manipulation of exciton polaritons and enabling specific applications driven by strong coupling. [ABSTRACT FROM AUTHOR]

Surface plasmon resonance (SPR) conventionally occurs at the interface of a thin metallic film and an external dielectric medium in fiber optics through core‐guided light. However, this work introduces theoretical and experimental evidence suggesting that the SPR in optical fibers can also be induced through light scattering from Au nanoparticles (NPs) on the thin metallic film, defined as nanoparticle‐induced SPR (NPI‐SPR). This method adheres to phase‐matching conditions between SPR dispersion curves and the wave vectors of scattered light from Au NPs. Experimentally, these conditions are met on an etched optical fiber, enabling direct interaction between light and immobilized Au NPs. Compared to SPR, NPI‐SPR exhibits stronger field intensity in the external region and wavelength tuning capabilities (750 to 1250 nm) by varying Au NP diameters (20 to 90 nm). NPI‐SPR demonstrates refractive index sensitivities of 4000 to 4416 nm per refractive index unit, nearly double those of typical SPR using the same optical fiber configuration sans Au NPs. Additionally, NPI‐SPR fiber configuration has demonstrated its applicability for developing biosensors, achieving a remarkable limit of detection of 0.004 nm for thrombin protein evaluation, a twenty‐fold enhancement compared to typical SPR. These findings underscore the intrinsic advantages of NPI‐SPR for sensing. [ABSTRACT FROM AUTHOR]

This study investigates the influence of LED radiation intensity on the photodeposition of gold nanoparticles onto TiO2 substrates, examining their physicochemical properties and photocatalytic activities. Utilizing a range of radiation intensities and wavelengths, TiO2-Au composites were synthesized and characterized through techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray (EDX), and X-ray photoelectron spectroscopy (XPS). The deposition process, markedly enhanced by shorter wavelengths and higher intensities, efficiently formed gold nanoparticles. This research distinctly highlights observable morphological changes in the nanoparticles; increased radiation intensity not only augmented the size but also altered their shape from spherical to hexagonal. These morphological transformations significantly improve the composites' light absorption and catalytic properties due to the surface plasmon resonance of the gold nanoparticles. Photocatalytic assessments, using metronidazole as a model pollutant, demonstrated that composites prepared with higher LED intensities showed significantly enhanced degradation capabilities compared to those synthesized with lower intensities. The findings underscore that manipulating photodeposition parameters can critically influence the structural and functional properties of TiO2-Au composites, potentially advancing their applications in environmental remediation and solar energy utilization. [ABSTRACT FROM AUTHOR]

Alpha‐synuclein oligomers play a crucial role in the early diagnosis of Parkinson's disease (PD). In this study, a mercaptoundecanoic acid (MUA)‐capped gold nanorod (GNR)‐coated and chitosan (CH)‐immobilized fiber optic probe has shown considerable sensitivity of its detection. The proposed U‐shaped fiber optic biosensor based on localized surface plasmon resonance (LSPR) was applied to detect α‐syn oligomer (OA) biomarker. By analyzing OA concentrations, the biosensor achieved a limit of detection of (LOD) 11 pM within the concentration range of 10–100 pM and the sensitivity value was found as 502.69 Δλ/RIU. Upon analysis of the CV% (coefficient of variation) and accuracy/recovery values, it is revealed that the sensor successfully fulfilled the criteria for success, displaying accuracy/recovery values within the range of 80%–120% and CV% values below 20%. This sensor presents significant advantages, including high sensitivity, specificity, and ability to detect very low concentrations of OA. In conclusion, the suggested U‐shaped fiber optic biosensor has the potential to be valuable in the early detection of PD from a clinical perspective. [ABSTRACT FROM AUTHOR]

This study explores the development of a PVC@Silver nanocomposite for enhanced detection of cadmium ions in water samples. Various characterization techniques confirmed the successful incorporation of silver nanoparticles into the polyvinyl chloride (PVC) matrix across different concentrations (1–4%). X-ray diffraction revealed the face-centered cubic crystalline structure of the silver nanoparticles, with the intensities of the (111), (200), (220), and (311) peaks increasing with higher Ag concentrations. The average crystallite sizes ranged from 26.1 nm (3% Ag) to 30.0 nm (2% Ag). Dynamic light scattering showed nanoparticle sizes of 24–43 nm, while zeta potential values of -24 to -40 mV indicated reasonable colloidal stability. Brunauer–Emmett–Teller (BET) surface area analysis demonstrated a decreasing surface area from 30.09 m2/g (1% Ag) to 25.27 m2/g (3% Ag), attributed to pore filling by silver nanostructures. Significantly, the PVC@Silver nanocomposite facilitated sensitive detection of Cd(II) ions using surface plasmon resonance (SPR), exhibiting an SPR angle shift of 26.30° with intensity values ranging from 10.80 (4% Ag) to 12.19 (3% Ag). UV–vis spectra revealed a prominent surface plasmon resonance band at 420–430 nm, indicating the presence of silver nanoparticles. The optical band gap varied from 4.51eV (1% Ag) to 4.12eV (4% Ag). [ABSTRACT FROM AUTHOR]

Metal-semiconductor bifunctional core-shell nanomaterials were studied using catalytic system Au@CdS as example that displayed surface plasmon resonance (SPR) effects and photocatalytic activity. Some mechanisms of photocatalytic activity of the studied nanomaterials were discussed. Surface-enhanced Raman spectroscopy (SERS) was used to monitor in situ the SPR-driven photocatalytic dimerization of 4-nitrothiophenol (pNTP) to 4,4′-dimercaptoazobenzene (DMAB). The transfer path of "hot" electrons in Au@CdS was tracked by monitoring Raman spectral changes of the probe molecule. Nanomaterials Au@CdS showed high catalytic activity in photocatalytic degradation of rhodamine 6G. The SPR-displaying metal-semiconductor nanocomposite was indicated to be an extremely promising photocatalytic and in-situ SERS probe. [ABSTRACT FROM AUTHOR]

Utilizing hot carriers for efficient plasmon‐mediated chemical reactions (PMCRs) to convert solar energy into secondary energy is one of the most feasible solutions to the global environmental and energy crisis. Finding a plasmonic heterogeneous nanostructure with a more efficient and reasonable hot carrier transport path without affecting the intrinsic plasmonic properties is still a major challenge that urgently needs to be solved in this field. Herein, the mechanism by which plasmon‐promoted interatomic hot electron redistribution on the surface of Au3Cu alloy nanoparticles promotes the electrocatalytic nitrogen reduction reaction (ENRR) is successfully clarified. The localized surface plasmon resonance (LSPR) effect can boost the transfer of plasmon hot electrons from Au atoms to Cu atoms, trigger the interatomic electron regulation of Au3Cu alloy nanoparticles, enhance the desorption of ammonia molecules, and increase the ammonia yield by approximately 93.9 %. This work provides an important reference for rationally designing and utilizing the LSPR effect to efficiently regulate the distribution and mechanism of plasmon hot carriers on the surface of heterogeneous alloy nanostructures. [ABSTRACT FROM AUTHOR]

Ultrafast spectroscopy can be used to study dynamic processes on femtosecond to nanosecond timescales, but is typically used for photoinduced processes. Several materials can induce ultrafast temperature rises upon absorption of femtosecond laser pulses, in principle allowing to study thermally activated processes, such as (catalytic) reactions, phase transitions, and conformational changes. Gold–silica core–shell nanoparticles are particularly interesting for this, as they can be used in a wide range of media and are chemically inert. Here we computationally model the temporal and spatial temperature profiles of gold nanoparticles with and without silica shell in liquid and gas media. Fast rises in temperature within tens of picoseconds are always observed. This is fast enough to study many of the aforementioned processes. We also validate our results experimentally using a poly(urethane‐urea) exhibiting a temperature‐dependent hydrogen bonding network, which shows local temperatures above 90 °C are reached on this timescale. Moreover, this experiment shows the hydrogen bond breaking in such polymers occurs within tens of picoseconds. [ABSTRACT FROM AUTHOR]

Gold nanostructures play a crucial role in medical applications, harnessing size and shape‐dependent properties. A prominent area of research is cancer treatment through the photothermal approach. Here, numerical simulation is explored to study the impact of gold nanostructure size, shape, and laser parameters on spatiotemporal temperature patterns during photothermal therapy (PTT). Spherical, rod, star, bipyramid, and cubic nanostructures in small, medium, and large sizes underwent 150 s of laser irradiation. COMSOL software, incorporating bioheat physics, precisely gauged thermal variations. The structural characteristics notably influence the temperature profiles, with medium‐sized rod, star, and bipyramid gold nanoparticles exhibiting superior thermal properties. Experimental validation of simulations focuses on the optimal nanostructure, synthesizing through the seed growth method. Transmission electron microscopy, UV‐visible spectroscopy, and X‐ray diffraction analysis confirm its proposed characteristics. Results demonstrate a robust correlation between experimental and simulation parameters, affirming precision. Findings showcase photothermal properties in line with theoretical predictions. The aim of this study is to determine the optimal gold nanostructure for bone cancer treatment using PTT, addressing the challenges presented by the dense and resilient nature of bone tissue and deep tumor locations. By utilizing multi‐physical modeling and simulations facilitated by COMSOL software, a novel method for pre‐clinical estimation is introduced. This research provides insights into each nanoparticle‐based PTT process prior to ex vivo and in vivo studies, offering a comprehensive understanding of the interplay between nanostructure characteristics and PTT outcomes. The approach contributes to advancing the field of cancer treatment by enhancing the predictability and effectiveness of nanoparticle‐mediated PTT. [ABSTRACT FROM AUTHOR]

The surface plasmon resonance (SPR) effect has garnered extensive attention in semiconductor photocatalysis for solar energy conversion, thanks to its remarkable optical properties. However, the majority SPR‐induced photocatalytic systems have been limited to achieving hydrogen evolution or oxygen evolution half reactions, and attaining overall water splitting on a SPR‐induced photocatalyst under visible light remains a formidable challenging. In this study, we employed a plasmonic photocatalyst Au/SrTiO3, and further enhanced its performance by doping aluminum (Al) into the SrTiO3 lattice (denoted as Au/SrTiO3:Al). By constructing reduction cocatalyst (RhCrOx) and oxidation cocatalyst (CoOOH), the Au/SrTiO3:Al photocatalyst successfully realizes photocatalytic overall water splitting with a stoichiometric ratio of H2 and O2 under visible light (λ≥440 nm). We revealed that the introduction of Al species effectively modified the electronic structure of SrTiO3, thereby enhancing the hydrogen evolution reaction in Au/SrTiO3:Al. Simultaneously, the RhCrOx and CoOOH cocatalysts synergistically capitalized on the short‐lived hot electrons and holes generated by the plasmonic Au/SrTiO3:Al photocatalyst, enabling to realize photocatalytic overall water splitting. This work offers a promising avenue for the rational design of plasmon‐induced overall water splitting photocatalysts through the integration of suitable cocatalysts and surface/interface engineering strategies. [ABSTRACT FROM AUTHOR]

One of the ways to create plasmonic nanoparticles is through a physical method of synthesizing by thermal evaporation in a vacuum, which was chosen for analysis through computer simulation. Experimental data on the initial and annealed silver nanoparticles obtained in this manner were studied. It was found that small Ag nanoparticles (D < 3.5 nm) exhibited nearly ideal FCC structure, while larger nanoparticles unexpectedly showed predominantly icosahedral or decahedral modifications. To assess the mechanisms behind these experimental results, a study on the stability of Ag nanocluster structures with diameters D = 2.0–10.0 nm was conducted using molecular dynamics. Based on computer analysis of synthesis processes, subsequent cooling of Ag nanoparticles, and their thermal annealing, it was demonstrated that the theoretical discrepancy in the structure of experimentally obtained nanoparticles could only be explained by significant deformation of small Ag nanoparticles occurring during their deposition on a substrate in a liquid state. Possible ways to control the structure of Ag nanoparticles were identified. The regularities identified through computer simulation can be utilized in the preparation of Ag nanoparticles using physical synthesis methods. [ABSTRACT FROM AUTHOR]

A series of Ag-TiO2 nanotube catalysts were prepared by electrochemical deposition. Doping of Ag nanoparticles was regulated by adjusting the deposition voltage, which altered the photocatalytic performance of the sample. The electrochemical properties of the Ag-TiO2 nanotubes were characterized using X-ray photoelectron spectroscopy, scanning electron microscopy (SEM), photoluminescence (PL) spectroscopy, and ultraviolet–visible (UV–vis) diffuse reflection spectroscopy. PL and UV–vis spectroscopy showed that the Ag-TiO2 nanotubes had a higher visible-light absorption activity and a lower photogenerated electron–hole pair recombination rate. SEM analysis showed that the highly ordered tubular structure of the TiO2 nanotubes was not disrupted after electrochemical deposition, and the size and quantity of the Ag nanoparticles deposited on the TiO2 nanotubes increased with increasing deposition voltage. The Ag-TiO2 nanotubes prepared at a deposition voltage of 1 V exhibited the highest hydrogen evolution efficiency, with a theoretical hydrogen production rate of 12.59 µmol∙cm−2∙h−1 under UV irradiation. This was 2.1-fold higher than that of pure TiO2 nanotubes and was attributable to the local surface plasmon resonance effect of Ag nanoparticles, which enhanced the visible light absorption by the TiO2 nanotubes. [ABSTRACT FROM AUTHOR]

The triggering receptor expressed on myeloid cells-2 (TREM2), a pivotal innate immune receptor, orchestrates functions such as inflammatory responses, phagocytosis, cell survival, and neuroprotection. TREM2 variants R47H and R62H have been associated with Alzheimer’s disease, yet the underlying mechanisms remain elusive. Our previous research established that TREM2 binds to heparan sulfate (HS) and variants R47H and R62H exhibit reduced affinity for HS. Building upon this groundwork, our current study delves into the interplay between TREM2 and HS and its impact on microglial function. We confirm TREM2’s binding to cell surface HS and demonstrate that TREM2 interacts with HS, forming HS-TREM2 binary complexes on microglia cell surfaces. Employing various biochemical techniques, including surface plasmon resonance, low molecular weight HS microarray screening, and serial HS mutant cell surface binding assays, we demonstrate TREM2’s robust affinity for HS, and the effective binding requires a minimum HS size of approximately 10 saccharide units. Notably, TREM2 selectively binds specific HS structures, with 6-O-sulfation and, to a lesser extent, the iduronic acid residue playing crucial roles. N-sulfation and 2- O-sulfation are dispensable for this interaction. Furthermore, we reveal that 6-O-sulfation is essential for HS-TREM2 ternary complex formation on the microglial cell surface, and HS and its 6-O-sulfation are necessary for TREM2-mediated ApoE3 uptake in microglia. By delineating the interaction between HS and TREM2 on the microglial cell surface and demonstrating its role in facilitating TREM2-mediated ApoE uptake by microglia, our findings provide valuable insights that can inform targeted interventions for modulating microglial functions in Alzheimer’s disease. [ABSTRACT FROM AUTHOR]

Research on the markers of autoimmune response in multiple sclerosis (MS) is still of great importance. The aim of our study was the evaluation of plasma 20S constitutive proteasome, 20S immunoproteasome, and cathepsin S concentrations as potential biomarkers of a relapsing‐remitting type of MS (RRMS). Surface plasmon resonance imaging (SPRI) biosensors were used for the evaluation of protein concentrations. Plasma 20S constitutive proteasome, 20S immunoproteasome, and cathepsin S concentrations were significantly higher in RRMS patients compared to the control group. All three parameters were characterized by excellent usefulness in differentiating MS patients from healthy individuals (AUC equal to or close to 1.000). The plasma concentration of analyzed parameters was not correlated with severity of disability in the course of RRMS (EDSS value), the number of years from the first MS symptoms, the number of years from MS diagnosis, or the number of relapses within the 24‐month observational period. Our study has shown that plasma concentrations of 20S constitutive proteasome, 20S immunoproteasome, and cathepsin S have promising potential in differentiating RRMS patients from healthy individuals. All of the analyzed parameters were found to be independent of the time of MS relapse and the severity of neurological symptoms. Hence, their potential as highly sensitive and independent circulating markers of RRMS suggests a stronger association with immunological activity (inflammatory processes) than with the severity of the disease. [ABSTRACT FROM AUTHOR]

Detecting biomolecular interactions without labeling has become possible because of surface plasmon resonance (SPR) sensing development. In this work, we report on investigating an SPR sensor designed especially for pregnancy detection. The sensor has a multi-layered structure of BK7, silver, platinum, graphene, and magnesium difluoride. The simulation and analysis have been conducted in both normal and pregnant urine with the effective refractive index values of 1.335, 1.34, 1.342, and 1.343 to detect the pregnancy. The structure is simulated using COMSOL Multiphysics software and optimized using the transfer matrix method. The sensitivity (S), detection accuracy (DA), full width at half maximum (FWHM), and figure of merit (FoM) optical properties have all been examined using this proposed SPR sensor. The sensor outperformed typical SPR sensors with an impressive sensitivity of 430 degree/RIU (refractive index unit) for pregnancy cases with three layers of platinum (Pt) and graphene (G) each, as determined by angular interrogation and MATLAB simulations. For the monolayer of Pt and G, other parameter-optimized value comes out to be 1.323 degree (FWHM), 0.755857 degree−1 (DA), 109.0383 RIU−1 (FoM) for non-pregnancy case and pregnancy case the computed values of FWHM, DA, and FoM are 1.409 degree, 0.709723 degree−1, and 111.1111 RIU−1 respectively. To accurately detect pregnancy biomarkers, the great sensitivity of the sensor makes it possible to detect even the smallest changes in the refractive index (RI) in the vicinity of the sensor surface. This novel sensor has potential uses in point-of-care testing and clinical diagnostics due to its ability to detect pregnancy quickly and non-invasively. [ABSTRACT FROM AUTHOR]

An ultrasensitive temperature sensor based on photonic crystal fiber (PCF) filled with liquid crystal and nanogold rods using surface plasmon resonance (SPR) is numerically analyzed in this paper. Gold is selected as a plasmonic metal to excite the SPR phenomenon. This paper shows a comparative study and inspects the effect of temperature sensing performance between one big gold rod and lattice of nanoscale gold rods. A finite element method (FEM) using COMSOL software has been applied for the investigation of some propagation characteristics of the PCF sensor. From the numerical results, it is observed that introducing an array of nanoscale gold rods helps to obtain high temperature sensitivity. After watchful investigation, the maximum sensitivities of 23 nm/°C have been achieved as the temperature changes from 30 °C to 40 °C. Compared with some previously reported temperature sensors, our proposed temperature sensor shows excellent sensitivity performances. [ABSTRACT FROM AUTHOR]

In this work, we utilized a biomimetic approach for targeting KATO (III) tumor cells and 3D tumoroids. Specifically, the binding interactions of the bioactive short peptide sequences ACSAG (A-pep) and LPHVLTPEAGAT (L-pep) with the fibroblast growth factor receptor (FGFR2) kinase domain was investigated for the first time. Both peptides have been shown to be derived from natural resources previously. We then created a new fusion trimer peptide ACSAG-LPHVLTPEAGAT-GASCA (Trimer-pep) and investigated its binding interactions with the FGFR2 kinase domain in order to target the fibroblast growth factor receptor 2 (FGFR2), which is many overexpressed in tumor cells. Molecular docking and molecular dynamics simulation studies revealed critical interactions with the activation loop, hinge and glycine-rich loop regions of the FGFR2 kinase domain. To develop these peptides for drug delivery, DOX (Doxorubicin) conjugates of the peptides were created. Furthermore, the binding of the peptides with the kinase domain was further confirmed through surface plasmon resonance studies. Cell studies with gastric cancer cells (KATO III) revealed that the conjugates and the peptides induced higher cytotoxicity in the tumor cells compared to normal cells. Following confirmation of cytotoxicity against tumor cells, the ability of the conjugates and the peptides to penetrate 3D spheroids was investigated by evaluating their permeation in co-cultured spheroids grown with KATO (III) and colon tumor-associated fibroblasts (CAFs). Results demonstrated that Trimer-pep conjugated with DOX showed the highest permeation, while the ACSAG conjugate also demonstrated reasonable permeation of the drug. These results indicate that these peptides may be further explored and potentially utilized to create drug conjugates for targeting tumor cells expressing FGFR2 for developing therapeutics. [ABSTRACT FROM AUTHOR]

In the present study, two A. melanocarpa berry extracts were used for the synthesis of silver nanoparticles (AgNPs). After the optimization of synthesis, the AgNPs were characterized using UV–Vis, FTIR, EDX, DLS, and STEM analyses. The stability in different media, phytotoxicity, as well as antimicrobial and antioxidant activities were also evaluated. The ideal synthesis conditions were represented by a 3 mM AgNO3 concentration, 1:9 extract:AgNO3 volume ratio, alkaline medium, and stirring at 40 °C for 120 min. The synthesis was confirmed by the surface plasmon resonance (SPR) peak at 403 nm, and the strong signal at 3 keV from the EDX spectra. FTIR analysis indicated that polyphenols, polysaccharides, and amino acids could be the compounds responsible for synthesis. Stability tests and the negative zeta potential values showed that phytocompounds also play a role in the stabilization and capping of AgNPs. The preliminary phytotoxicity studies on T. aestivum showed that both the extracts and their corresponding AgNPs had an impact on the growth of roots and shoots as well as on the microscopic structure of leaves. The synthesized AgNPs presented antimicrobial activity against S. aureus, E. coli, and C. albicans. Moreover, considering the results obtained in the lipoxygenase inhibition, the DPPH and hydroxyl scavenging activities, and the ferrous ion chelating assay, AgNPs exhibit promising antioxidant activity. [ABSTRACT FROM AUTHOR]

BiOBr with different preferred growth orientation facets would show a different photocatalytic performance. When decorated in situ with metallic Bi nanoparticles, Bi/BiOBr would commonly display an enhanced photocatalytic performance. In this paper, the BiOBr nanoplates with preferred growth orientation (102) facet and (110) facet were first synthesized using a hydrothermal method. Then, some metallic Bi nanoparticles were modified in situ onto the (110)BiOBr nanoplates, which was expected to show a much more enhanced photocatalytic performance. All samples were characterized using XRD, FE-SEM, TEM, N2 adsorption–desorption, UV–vis and XPS. FE-SEM and TEM images showed that the grain size of the metallic Bi particles was about 5 nm to 10 nm. UV–vis spectra showed that, after some metallic Bi nanoparticles were modified on (110)BiOBr nanoplates, the light absorbance in the visible light region at 400–700 nm became stronger and their optical band gap became larger. N2 adsorption–desorption tests showed that the Bi(x)/(110)BiOBr nanosheets possessed larger specific surface areas than that of the (102)BiOBr and (110)BiOBr nanoplates. The XPS results showed that Bi(x)/(110)BiOBr contained more oxygen vacancies and a more negative value of the conduction band minimum. The photocatalytic performance of (102)BiOBr, (110)BiOBr and Bi(x)/(110)BiOBr were tested in the photocatalytic degradation of rhodamine B under visible light irradiation for 2 h; their photocatalytic efficiency was 45%, 75% and 80%, respectively. In comparison to (102)BiOBr, (110)BiOBr exhibited much higher photocatalytic activity, while for Bi(x)/(110)BiOBr, despite the surface Plasmon resonance effect, a larger specific surface area and more oxygen vacancies, the enhancement of the efficiency was limited, which might have resulted from the larger optical band gap. [ABSTRACT FROM AUTHOR]

Using electrospun nanofibers doped with TiO2 and rare-earth ion Ho3+ as the matrix, and sodium gluconate as the reducing agent, Bi(NO3)3 was reduced using hydrothermal technology to produce Bi@Ho3+:TiO2 composite fiber materials. The materials' phase, morphology, and photoelectric properties were characterized using various analytical testing methods, including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS), and transient photocurrent (IP). During the hydrothermal process, it was confirmed that Bi3+ was reduced by sodium gluconate to form pure Bi nanoparticles, which combined with Ho3+:TiO2 nanofibers to form heterojunctions. By leveraging the surface plasmon resonance (SPR) effect of metallic Bi and the abundant energy level structure and 4f electron transition properties of rare-earth Ho3+, the TiO2 nanofibers underwent dual modification, effectively enhancing the photocatalytic activity and stability of TiO2. Under visible light irradiation, the rate of hydrogen production through water decomposition reached 43.6 μmol·g−1·h−1. [ABSTRACT FROM AUTHOR]

Hepatocellular carcinoma (HCC) is a significant global health concern. However, there are limited effective treatments available for it. The use of natural products in the management and treatment of HCC is gaining more attention. Baicalein is a flavonoid compound that has been reported to have antitumor activities in HCC. However, the direct binding targets of baicalein are still unknown. Therefore, we used the DNA‐programmed affinity labeling method to identify the target of baicalein and validated its function in HCC cells. We set blank and competitive DNA probes as negative controls. The results showed that baicalein had 136 binding targets, of which 13 targets were differently expressed in HCC tissues. The enriched cellular process of these targets was apoptosis, which involved MAPK9. We tested the binding affinity of baicalein with MAPK9 as 89.7 nM (Kd) by surface plasmon resonance and analyzed the binding sites by virtual docking. Notably, the binding of baicalein with MAPK9 increased the protein levels of MAPK9 itself and the related downstream apoptosis signaling, triggering the apoptosis of HCC cells. However, the inhibitor of MAPK9, SP600125, blocked the baicalein‐induced apoptosis, and the amounts of MAPK9 and downstream molecules were also decreased, indicating that baicalein acted through MAPK9 to induce apoptosis of HCC cells. In conclusion, we used the DNA‐programmed affinity labeling method to identify the direct‐binding target MAPK9 of baicalein and validated its function in baicalein‐induced apoptosis of HCC cells, which would be helpful to understand and use baicalein in HCC therapy. [ABSTRACT FROM AUTHOR]

In this study, we report the synthesis of silver nanoparticles (AgNP's) by reducing silver ions from a solution of silver nitrate with an aqueous extract from Azadirachta indica. Using silver ions as the catalyst, nanoparticles were formed in 8 min without the use of toxic chemicals. As evidenced by UV-vis spectroscopy, a broad surface plasmon resonance spectrum at 225 nm was detected, which indicates the colloidal solution of silver nanoparticles is stable and produces silver nanoparticles. As revealed by the fourier transform-infrared spectrometer (FTIR) analysis, the flower extract contained a variety of biomolecules that acted as capping and reducing agents for the synthesis of AgNPs. As determined by X-ray diffraction (XRD), silver nanoparticles displayed a crystalline structure and ranged in size from 18 to 39 nm. In addition to these findings, transmission electron microscopy (TEM) images showed that the silver nanoparticles were spherical and rod-shaped, as confirmed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDAX). A variety of pathogenic bacteria, such as Klebsiella pneumoniae, Escherichia coli, Bacillus subtilis and Staphylococcus aureus, were tested against AgNP's antibacterial properties. A significant inhibition zone was observed for Escherichia coli when AgNPs were applied at different concentrations. Silver nanoparticles were shown to have antidiabetic effects through a diphtheria assay with inhibition rates ranging from 31.09% to 83.33% for concentrations of 50–250 μ g/mL. As researchers seek natural sources of compounds with potential health benefits, silver nanoparticles were also investigated for their antioxidant properties. Silver nanoparticles (AgNPs) were synthesized, using an aqueous extract from Azadirachta indica, as a reducing agent. UV-vis spectroscopy, shown a broad surface plasmon resonance spectrum at 225 nm, where SEM and HRTEM analyses revealed that the AgNPs were spherical and rod-shaped with sizes ranging from 18 to 39 nm. The AgNPs demonstrated significant antimicrobial properties against various pathogens and exhibited potent antioxidant activity, suggesting their potential for therapeutic applications. [ABSTRACT FROM AUTHOR]

Cancer remains a significant global health burden, claiming countless lives annually and incurring substantial direct and indirect economic costs. Despite advancements in therapeutic modalities, conventional cancer treatments, including chemotherapy, radiotherapy and surgery, are often hampered by limitations such as insufficient efficacy, dose-dependent side effects, high costs and patient tolerability. This has spurred extensive research into novel therapeutic approaches for this life-threatening disease. Metal nanoparticles (MNPs) have emerged as promising tools in cancer therapy due to their unique physicochemical properties spanning the past two decades. Owing to their size similarity to biological molecules, MNPs possess the inherent ability to penetrate cellular barriers, making them ideal carriers for targeted drug delivery. These multifunctional nanoplatforms offer distinct advantages over conventional therapeutics by enabling targeted delivery of anticancer agents to specific tumor sites, thereby enhancing therapeutic efficacy and minimizing systemic side effects. Photodynamic therapy and sonodynamic therapy represent particularly promising strategies that leverage MNPs for cancer treatment. This review delves into the potential applications of MNPs in modulating the tumor microenvironment, paving the way for the exploration of this vast and rapidly evolving field of nanomedicine. Advancements in nanotechnology have led to the development of various metallic nanoparticles including gold, silver, platinum, zinc, palladium, and iron which play crucial roles in tumor diagnostics and treatment. These nanoparticles leverage surface plasmon resonance to enhance the detection and targeting of tumor cells, offering new possibilities in cancer therapy and personalized medicine. [ABSTRACT FROM AUTHOR]

Lipopolysaccharide (LPS) triggers a severe systemic inflammatory reaction in mammals, with the dimerization of TLR4/MD-2 upon LPS stimulation serving as the pivotal mechanism in the transmission of inflammatory signals. Ginsenoside Rh2 (G-Rh2), one of the active constituents of red ginseng, exerts potent anti-inflammatory activity. However, whether G-Rh2 can block the TLR4 dimerization to exert anti-inflammatory effects remains unclear. Here, we first investigated the non-cytotoxic concentration of G-Rh2 on RAW 264.7 cells, and detected the releases of pro-inflammatory cytokines in LPS-treated RAW 264.7 cells, and then uncovered the mechanisms involved in the anti-inflammatory activity of G-Rh2 through flow cytometry, fluorescent membrane localization, Western blotting, co-immunoprecipitation (Co-IP), molecular docking and surface plasmon resonance (SPR) analysis in LPS-stimulated macrophages. Our results show that G-Rh2 stimulation markedly inhibited the secretion of LPS-induced interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and nitric oxide (NO). Additionally, G-Rh2 blocked the binding of LPS with the membrane of RAW 264.7 cells through direct interaction with TLR4 and MD-2 proteins, leading to the disruption of the dimerization of TLR4 and MD-2, followed by suppression of the TLR4/NF-κB signaling pathway. Our results suggest that G-Rh2 acts as a new inhibitor of TLR4 dimerization and may serve as a promising therapeutic agent against inflammation. [ABSTRACT FROM AUTHOR]

The incorporation of gold nanoparticles (GNPs) into retinal imaging signifies a notable advancement in ophthalmology, offering improved accuracy in diagnosis and patient outcomes. This review explores the synthesis and unique properties of GNPs, highlighting their adjustable surface plasmon resonance, biocompatibility, and excellent optical absorption and scattering abilities. These features make GNPs advantageous contrast agents, enhancing the precision and quality of various imaging modalities, including photoacoustic imaging, optical coherence tomography, and fluorescence imaging. This paper analyzes the unique properties and corresponding mechanisms based on the morphological features of GNPs, highlighting the potential of GNPs in retinal disease diagnosis and management. Given the limitations currently encountered in clinical applications of GNPs, the approaches and strategies to overcome these limitations are also discussed. These findings suggest that the properties and efficacy of GNPs have innovative applications in retinal disease imaging. [ABSTRACT FROM AUTHOR]

In this paper, a three-layer structure of silver particle (AgNP)-dielectric-metal is proposed and constructed based on the characteristics of AgNPs that can excite LSPR (Localized Surface Plasmon Resonance) in free space. In order to overcome the problem of AgNPs easily oxidizing in the air, this paper synthesizes AgNPs using the improved Tollens method and effectively suppresses the coffee-ring effect by changing the solution evaporation conditions, so that the distribution of AgNPs in the deposition area is relatively uniform. The structure proposed in this paper takes advantage of the flexibility of nanoparticle application. The AgNPs deposited on the dielectric layer can effectively localize energy and regulate the LSPR of the device well. The structure can not only achieve precise regulation of the LSPR resonance peak of AgNPs but also can be used as a SERS substrate. [ABSTRACT FROM AUTHOR]

A novel highly sensitive D-shaped photonic crystal fiber-based surface plasmon resonance (PCF-SPR) sensor for dual parameters of refractive index and temperature detecting is proposed. A PCF cladding polishing provides a D-shape design with a gold (Au) film coating for refractive index (RI) sensing (Core 1) and a composite film of silver (Ag) and polydimethylsiloxane (PDMS) for temperature sensing (Core 2). Comsol Multiphysics 5.5 is used to design and simulate the proposed sensor by the finite element method (FEM). The proposed sensor numerically provides results with maximum wavelength sensitivities (WSs) of 51,200 and 56,700 nm/RIU for Core 1 and 2 as RI sensing while amplitude sensitivities are −98.9 and −147.6 RIU−1 with spectral resolution of 1.95 × 10−6 and 1.76 × 10−6 RIU, respectively. Notably, wavelength sensitivity of 17.4 nm/°C is obtained between −20 and −10 °C with resolution of 5.74 × 10−3 °C for Core 2 as temperature sensing. This sensor can efficiently work in the analyte and temperature ranges of 1.33–1.43 RI and −20–100 °C. Due to its high sensitivity and wide detection ranges, both in T and RI sensing, it is a promising candidate for a variety of applications, including chemical, medical, and environmental detection. [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]

A new analytical method, based on SPRi biosensors, has been developed for the simultaneous determination of the pro-angiogenic factors HIF-1α, angiopoietin-2 (ANG-2), and interleukin-1β (IL-1β) in biological fluids. These proteins take part in the process of angiogenesis, i.e., the creation of new blood vessels, which is a key stage of cancer development and metastasis. A separate validation process was carried out for each individual compound, indicating that the method can also be used to study one selected protein. Low values of the limit of detection (LOD) and quantification (LOQ) indicate that the developed method enables the determination of very low concentrations, in the order of pg/mL. The LOD values obtained for HIF-1α, ANG-2, and IL-1β were 0.09, 0.01, and 0.01 pg/mL, respectively. The LOQ values were 0.27, 0.039, and 0.02 pg/mL, and the response ranges of the biosensor were 5.00–100.00, 1.00–20.00, and 1.00–15.00 pg/mL. Moreover, determining the appropriate validation parameters confirmed that the design offers high precision, accuracy, and sensitivity. To prove the usefulness of the biosensor in practice, determinations were made in plasma samples from a control group and from a study group consisting of patients with diagnosed bladder cancer. The preliminary results obtained indicate that this biosensor can be used for broader analyses of bladder cancer. Each of the potential biomarkers, HIF-1α, ANG-2, and IL-1β, produced higher concentrations in the study group than in the control group. These are preliminary studies that serve to develop hypotheses, and their confirmation requires the analysis of a larger number of samples. However, the constructed biosensor is characterized by its ease and speed of measurement, and the method does not require special preparation of samples. SPRi biosensors can be used as a sensitive and highly selective method for determining potential blood biomarkers, which in the future may become part of the routine diagnosis of cancers. [ABSTRACT FROM AUTHOR]

Surface-Enhanced Raman Spectroscopy (SERS) is a powerful, non-destructive technique for enhancing molecular spectra, first discovered in 1974. This study investigates the enhancement of Raman signals from single- and few-layer molybdenum disulfide (MoS2) when interacting with silver nanoparticles. We synthesized a MoS2 membrane primarily consisting of monolayers and bilayers through a wet chemical vapor deposition method using metal salts. The silver nanoparticles were either directly grown on the MoS2 membrane or placed beneath it. Raman measurements revealed a significant increase in signal intensity from the MoS2 membrane on the silver nanoparticles, attributed to localized surface plasmon resonances that facilitate SERS. Our results indicate that dichalcogenide/plasmonic systems have promising applications in the semiconductor industry. [ABSTRACT FROM AUTHOR]

Surface enhanced fluorescence (SEF) based on noble metal nanoparticles is an effective means to achieve high sensitivity in fluorescence detection. Currently, the physical mechanism behind enhanced fluorescence is not fully understood. This paper measures the fluorescence signals of Dihydroporphyrin f methyl ether (CPD4) under both single-photon and two-photon excitation based on submicrometer silver particles with rough morphologies, achieving enhancement factors of 34 and 45 times, respectively. On this basis, by combining the radiative field characteristics produced by the silver particles, a stimulated radiation model of molecules is established to elucidate the changes in the molecular photophysical process when influenced by silver particles. Moreover, the fluorescence lifetime of the molecules was measured, showing that the presence of silver particles induces an increase in the molecular radiative decay rate, causing the fluorescence lifetime to decay from 3.8 ns to 3 ns. The results indicate that the fluorescence enhancement primarily originates from the submicrometer silver particles' enhancement effect on the excitation light. Additionally, the fluorescence signal emitted by the molecules couples with the silver particles, causing the local surface plasmon resonances generated by the silver particles to also emit light signals of the same frequency. Under the combined effect, the fluorescence of the molecules is significantly enhanced. The findings provide a theoretical foundation for understanding the fluorescence enhancement mechanism of silver particles, adjusting the enhancement effect, and developing enhanced fluorescence detection devices based on submicrometer silver particles, holding significant practical importance. [ABSTRACT FROM AUTHOR]

Ultraviolet (UV) photodetectors (PDs) based on nanowire (NW) hold significant promise for applications in fire detection, optical communication, and environmental monitoring. As optoelectronic devices evolve towards lower dimensionality, multifunctionality, and integrability, multicolor PDs have become a research hotspot in optics and electronic information. This study investigates the enhancement of detection capability in a light-trapping ZnO NW array through modification with Pt nanoparticles (NPs) via magnetron sputtering and hydrothermal synthesis. The optimized PD exhibits superior performance, achieving a responsivity of 12.49 A/W, detectivity of 4.07 × 1012 Jones, and external quantum efficiency (EQE) of 4.19 × 103%, respectively. In addition, the Pt NPs/ZnO NW/ZnO PD maintains spectral selectivity in the UV region. These findings show the pivotal role of Pt NPs in enhancing photodetection performance through their strong light absorption and scattering properties. This improvement is associated with localized surface plasmon resonance induced by the Pt NPs, leading to enhanced incident light and interfacial charge separation for the specialized configurations of the nanodevice. Utilizing metal NPs for device modification represents a breakthrough that positively affects the preparation of high-performance ZnO-based UV PDs. [ABSTRACT FROM AUTHOR]

In this study, an easy, efficient, economical, and eco-friendly green bio-synthesis method was utilized to synthesize silver nanoparticles (AgNPs) using the extracts of four plants: Ginkgo biloba, Cichorium Intybus, Adiantum Capillus-Veneris, and Rosmarinus Officinalis. The synthesis of AgNPs was confirmed by using a uv-vis spectrometer, which showed distinct surface plasmon resonance (SPR) bands. The surface of AgNPs was characterized using scanning electron microscopy and Fourier-transform infrared spectroscopy. The anti-inflammatory activity of Tenoxicam/Meloxicam-loaded AgNPs has been studied using the inhibition of albumin denaturation method. Tenoxicam-loaded AgNPs showed higher % Inhibition, but Meloxicam-loaded AgNPs showed lower % Inhibition. Furthermore, the AgNPs showed excellent antimicrobial activity on both Gram-negative and Gram-positive bacteria. [ABSTRACT FROM AUTHOR]

Silver nanoparticles are among the most widely researched and used for nanotechnology-derived structures due to their extraordinary inherent optical properties, chemical stability, catalytic activity, and high conductivity. These idiosyncratic properties can be attributed to their unique physico-chemical characteristics, such as ultrafine sizes, high surface area, diverse shapes, and strong localized surface plasmon resonance. These distinctive features can be tailored using various physical, chemical, and biological synthesis methods. Various physical techniques are viable for producing silver nanoparticles on a large scale, but they suffer from drawbacks such as high-power consumption, expensive set-up, and limited control over nanoparticle size distribution. Chemical methods provide benefits like high yield, consistent shape and size distribution, and cost efficiency, but the residual toxicity of the chemicals involved hinders their biological applications. Biological synthesis approaches effectively overcome the limitations of both physical and chemical methods by eliminating the need for hazardous chemicals, requiring less energy, enabling diverse nanoparticle morphologies, and offering eco-friendliness and exceptional biocompatibility. The novel and promising properties of nanosilver-based biomaterials have been demonstrated to be suitable for a wide range of pharmacological and therapeutic biomedical applications. Their extensive application in wound healing, dentistry, cardiovascular disease treatment, nerve tissue engineering, cancer treatment, and biosensing can be attributed to their inherent antimicrobial and antibiofilm activity, antithrombotic properties, potential for nerve regeneration, photothermal conversion efficiency and sensitivity, respectively. This review discusses the different methods employed for synthesising silver nanoparticles and focuses on using nanosilverbased biomaterials for various biomedical applications. [ABSTRACT FROM AUTHOR]

Purpose: The unsatisfactory efficacy of PD-L1 antibodies in glioblastoma (GBM) is largely due to the temporal and spatial heterogeneity of PD-L1 expression. Molecular imaging can enhance understanding of the tumor immune microenvironment and guide immunotherapy. However, highly sensitive imaging agents capable of effectively visualizing PD-L1 heterogeneity are limited. This study introduces a novel PET tracer, offering improved imaging of PD-L1 heterogeneity in GBM xenografts, with a comparative analysis to [18F]AlF-NOTA-WL12. Methods: [18F]AlF-NOTA-PCP2 was synthesized with high purity and its affinity for PD-L1 was characterized using surface plasmon resonance (SPR) and cell binding assays. Its specificity for PD-L1 was evaluated both in vitro using various cell lines and in vivo with GBM xenograft models in NOD/SCID mice. PET/CT imaging was conducted to evaluate the tracer's biodistribution, pharmacokinetics, and ability to quantify tumoral spatial heterogeneity of PD-L1 expression. A focused comparative analysis between [18F]AlF-NOTA-PCP2 and [18F]AlF-NOTA-WL12 was conducted, examining binding affinity, biodistribution, pharmacokinetics, and imaging effectiveness in GBM xenografts. Additionally, human radiation dosimetry estimates compared the safety profiles of both tracers. Results: [18F]AlF-NOTA-PCP2 demonstrated high radiochemical purity (> 95%) and a strong affinity for PD-L1, comparable to [18F]AlF-NOTA-WL12. In vitro and in vivo studies confirmed its specificity for PD-L1, with increased uptake in PD-L1 expressing cells and tumors. Toxicological profiles indicated no significant abnormalities in serum biochemical indicators or major organ tissues. MicroPET/CT imaging showed [18F]AlF-NOTA-PCP2's effectiveness in visualizing PD-L1 expression levels and spatial heterogeneity in GBM xenografts. Comparative studies revealed [18F]AlF-NOTA-PCP2's improved pharmacokinetic properties, including higher tumor-to-blood ratios and lower nonspecific liver uptake, as well as reduced radiation exposure compared to [18F]AlF-NOTA-WL12. Conclusion: [18F]AlF-NOTA-PCP2 distinguishes itself as an exceptionally sensitive PET/CT tracer, adept at non-invasively and accurately quantifying PD-L1 expression and its spatial heterogeneity in tumors, especially in GBM. Its favorable pharmacokinetic properties, safety profile, and high affinity for PD-L1 highlight its potential for enhancing the precision of cancer immunotherapy and guiding individualized treatment strategies. While promising, its clinical translation, especially in brain imaging, necessitates further validation in clinical trials. [ABSTRACT FROM AUTHOR]

Herein, a newly synthesized intermediate, piperazine-based Schiff base (PBSB) gas sensor was fabricated by the Schiff base condensation of amino functionalized methylpiperazine with aromatic aldehyde containing nitro substituent. This organic sensor material was structurally identified with spectroscopic techniques such as FTIR, HRMS, 1H- and 13C-NMR. The designed sensor candidate was explored for its optical response to chlorinated volatile organic compounds, namely trichloroethylene, dichloromethane and chloroform in the light of structure–property relationship investigation by using surface plasmon resonance (SPR) technique. The results showed that Schiff bases could be candidates for chlorinated vapour sensing materials with their good response and reversibility. Concordantly, compound PBSB exhibited good response against chlorinated solvent vapours aided by the electron-withdrawing group on benzene ring that promoted better intermolecular interactions and opened up a new strategy to create a novel set of responsive materials for gas sensing applications. In addition, the adsorption kinetics of SPR data obtained from PBSB spun film on exposure to these chlorinated vapours at different concentrations was also evaluated using the Elovich Model. The values of the initial adsorption rate, a and Elovich constant, b were analysed depending on the concentration values and the highest values were obtained for dichloromethane between 372.92 and 4377.53 ppm/mm2. [ABSTRACT FROM AUTHOR]

Antibiotic success rates are decreasing as drug-resistant bacteria become more prevalent, prompting the development of new therapeutic drugs. Herein, we demonstrated the antimicrobial activity of sarsaparilla root extract fabricated silver nanoparticles (sAgNPs). The UV–Visible spectra revealed that the surface Plasmon resonance maxima of sAgNPs were at 415 nm. Transmission electron microscopy confirms that the particles are spherical with size of 12–35 nm. The minimum inhibitory concentration (MIC) of sAgNPs against Escherichia coli, uropathogenic Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus was 62.5, 62.5, 62.5, 62.5, 125 and 125 µM, respectively. At 1X MIC, sAgNPs induces excess reactive oxygen species (ROS) production and disturbs the bacteria membrane intergity, causing cytoplamic membrane depolarization. Interestingly, antibacterial activity of sAgNPs was considerably reduced in the presence of an antioxidant, N-acetyl cysteine, suggesting that ROS-induced membrane damage is a plausible cause of cell death. In contrast to many studies that only report the in vitro activity of NPs, we determined the in vivo antibacterial efficacy using the zebrafish model. It was found that sAgNPs protect fish from infection by inhibiting bacterial growth and eliminating them from the fish. In addition, the catalytic potential of sAgNPs for wastewater decontamination was demonstrated by degrading organic pollutants such as methyl orange, congo red, reactive black, and acid blue. The pollutants degraded in less than 10 min, and the reaction follows pseudo-first-order kinetics. As a proof of concept, the catalytic potential of sAgNPs in degrading mixed dyes to satisfy industrial wastewater treatment needs was established. In summary, sAgNPs have the potential to act as nanocatalysts and nano-drugs, addressing key challenges in medical and environmental research. [ABSTRACT FROM AUTHOR]

Liver fibrosis is a key and reversible stage in the progression of many chronic liver diseases to cirrhosis or hepatocellular carcinoma. Forsythiaside-A (FTA), a main compound isolated from Forsythiae Fructus, has an excellent liver protective activity. This study aims to investigate the efficacy of FTA in improving cholestatic liver fibrosis. Bile-duct-ligation (BDL) was conducted to induce liver fibrosis in mice. Hepatic collagen deposition was evaluated by Masson and Sirus red staining. The bile acid spectrum in the liver and serum was analyzed by mass spectrometry. Liver oxidative stress injury and mitochondria damage were observed by using Mito-Tracker Red fluorescence staining, transmission electron microscopy, etc. The level of ferrous iron (Fe2+) and the expression of ferroptosis-associated molecules were detected. The binding between FTA and its target protein was confirmed by Co-immunoprecipitation (Co-IP), cellular thermal shift assay (CETSA), drug affinity responsive target stability (DARTS) and surface plasmon resonance (SPR). Our results demonstrated that FTA alleviated BDL-induced liver fibrosis in mice. FTA did not decrease the elevated amount of bile acids in BDL-treated mice, but reduced the bile acid-induced mitochondrial damage, oxidative stress and ferroptosis in hepatocytes, and also induced nuclear factor erythroid 2-related factor-2 (Nrf2) activation. In Nrf2 knock-out mice, the FTA-provided protection against BDL-induced liver fibrosis was disappeared, and FTA's inhibition on mitochondrial damage, oxidative stress and ferroptosis were lowered. Further results displayed that FTA could directly bind to Kelch-like ECH-associated protein-1 (Keap1), thereby activating Nrf2. Moreover, the BDL-induced liver fibrosis was markedly weakened in liver-specific Keap1 knockout mice. Hence, this study suggests that FTA alleviated the BDL-induced liver fibrosis through attenuating mitochondrial damage and ferroptosis in hepatocytes by activating Nrf2 via directly binding to Keap1. [Display omitted] • FTA improved BDL-induced liver fibrosis in mice. • FTA attenuated ferroptosis induced by TCA and TCDCA in hepatocytes. • Nrf2 was critical for FTA's efficacy in reducing ferroptosis. • Nrf2 was critical for FTA's efficacy in improving liver fibrosis. • FTA induced Nrf2 nuclear translocation by directly binding to Keap1. [ABSTRACT FROM AUTHOR]

The scorpion-derived peptide margatoxin (MgTx) can make it possible to create novel and targeted medications for treatment of cancer. In this study, for the first time, we report an investigation of the human serum albumin (HSA) protein interaction with MgTx in aqueous solution. For this, biophysical methods including spectral, surface plasmon resonance (SPR), zeta potential and also in silico molecular docking technique at physiological conditions were used for examining kinetic binding and thermodynamic data. This interaction was done for a series of MgTx concentrations at three temperatures. The comparison of the KD kinetic value at 308 ° K and 298 ° K in SPR and UV spectroscopy shows that the complex between the MgTx and HSA has high strength at lower temperatures. The resulted positive data for ΔH and ΔS show that the major interaction force involved in the formation of the MgTx/HSA complex is hydrophobic forces. Also, the decreasing of zeta-potential values by adding of MgTx concentrations confims that the MgTx molecules could bind to HSA more by hydrophobic forces. In addition, according to the docking results, there are a very small number of strong interactions such as hydrogen bonds and salt bridges compared to the hydrophobic forces in the HSA and MgTx interaction. [ABSTRACT FROM AUTHOR]

Bi/BiOCl with oxygen vacancies composite was synthesized through a facile and rapid in situ surface reduction of BiOCl, utilizing NaBH4 as the reductant. The reduction process yielded metallic Bi nanoparticles on the surface of BiOCl and meanwhile created the oxygen vacancies within the BiOCl lattice. As a consequence, the as‐synthesized Bi/BiOCl composites exhibited a substantially enhanced visible‐light absorption capacity, whereas pure BiOCl was only responsive to ultraviolet light. Additionally, the Bi/BiOCl composite demonstrated a markedly accelerated photodegradation rate of Rhodamine, exceeding that of pure BiOCl and P25 by a factor of 6.10 and 19.74, respectively. The density functional theory (DFT) calculation was carried out to estimate the band structural and electronic properties of samples. Based on systematic analysis, the underlying mechanism was attributed to the extended responsive light range due to the surface plasma resonance of metallic Bi and the formation of oxygen vacancy energy level. Moreover, the electron sink effect of Bi nanoparticles was found to suppress the recombination of photoinduced charges, further contributing to the enhanced photocatalytic performance of Bi/BiOCl. [ABSTRACT FROM AUTHOR]

Background: Numerous studies suggest a progressive accumulation of post-translationally modified peptides within amyloid fibrils, including isoaspartate (isoD) modifications. Here, we generated and characterised novel monoclonal antibodies targeting isoD-modified transthyretin (TTR). The antibodies were used to investigate the presence of isoD-modified TTR in deposits from transthyretin amyloidosis patients and to mediate antibody-dependent phagocytosis of TTR fibrils. Methods: Monoclonal antibodies were generated by immunisation of mice using an isoD-modified peptide and subsequent hybridoma generation. The antibodies were characterised in terms of affinity and specificity to isoD-modified TTR using surface plasmon resonance, transmission electron microscopy and immunohistochemical staining of human cardiac tissue. The potential to elicit antibody-dependent phagocytosis of TTR fibrils was assessed using THP-1 cells. Results: We developed two mouse monoclonal antibodies, 2F2 and 4D4, with high nanomolar affinity for isoD-modified TTR and strong selectivity over the unmodified epitope. Both antibodies show presence of isoD-modified TTR in human cardiac tissue, but not in freshly purified recombinant TTR, suggesting isoD modification only present in aged fibrillar deposits. Likewise, the antibodies only facilitated phagocytosis of TTR fibrils and not TTR monomers by THP-1 cells. Conclusions: These antibodies label aged, non-native TTR deposits, leaving native TTR unattended and thereby potentially enabling new therapeutic approaches. [ABSTRACT FROM AUTHOR]

Tanshinone I (Tan I) has been proven to exert an anti-inflammatory effect, but the complete mechanism remains unclear. In this study, Tan I was described to have no effect on Syk expression in resting or LPS-stimulated macrophages ex vivo , but dramatically suppressed Syk phosphorylation and CD80, CD86, and IL-1β expression of macrophages. The inflammatory activity of macrophages in ApoC3-transgenic (ApoC3TG) mice is upregulated by Syk activation. Tan I was determined to downregulate Syk phosphorylation and inflammatory activity of macrophages in ApoC3TG mice, both ex vivo and in vivo. Intraperitoneal injection of Tan I (4 mg/kg) effectively alleviated DSS-induced colitis in mice, accompanying with suppressing the activation of intestinal macrophages. Mechanistically, Tan I-treated macrophages exhibited a decrease in cytoplasmic ROS, NLRP3, GSDMD, and IL-1β, which suggested that the alternative pathway of inflammasome activation in macrophages was suppressed. The SPR assay demonstrated that Tan I bound to Syk protein with a dissociation constant (KD) of 2.473 × 10−6 M. When Syk expression was knocked down by its shRNA, the inhibitory effects of Tan I on macrophages were blocked. Collectively, Tanshinone I effectively alleviated DSS-induced colitis in mice by inhibiting Syk-stimulated inflammasome activation, hence suppressing the inflammatory activity of macrophages. • Tanshinone I inhibited p-Syk and limited the inflammatory activity of macrophages. • Tanshinone I effectively alleviated DSS-induced colitis in mice by limiting the activation of intestinal macrophages. • Tanshinone I-treated macrophages exhibited a decrease in alternative pathway of inflammasome activation. • Direct binding of Tanshinone Ⅰ to Syk was confirmed by the surface plasmon resonance assay. [ABSTRACT FROM AUTHOR]