Metal Nanoparticles Research Articles

Quantifying Localized Surface Plasmon Resonance Induced Enhancement on Metal@Cu2O Composites for Photoelectrochemical Water Splitting.

The localized surface plasmon resonance (LSPR) of metal nanoparticles can substantially enhance the activity of photoelectrocatalytic (PEC) reactions. However, quantifying the respective contributions of different LSPR mechanisms to the enhancement of PEC performance remains an urgent challenge. In this work, Cu@Cu2O composites prepared by annealing Cu2O under an inert atmosphere and electrodeposited metal@Cu2O composites (MED@Cu2O, MED = CuED, AuED, AgED, PdED, PtED) are employed as platform materials to investigate the LSPR effect on the PEC hydrogen evolution reaction (HER). All the composites exhibited remarkably LSPR-enhanced activity toward PEC HER. The contributions of two LSPR mechanisms, plasmon induced resonance energy transfer (PIRET) and hot electron transfer (HET), to the photocurrent on Cu@Cu2O and CuED@Cu2O are quantified by using different bands of incident light. Moreover, using MED@Cu2O composites, the effects of both the metal species and the applied potential on HET are quantitatively investigated. The results reveal that a pronounced HET enhancement occurs only when the LSPR peak energy is lower than the semiconductor bandgap energy (Eg) and that HET strengthens as the applied potential becomes more negative for PEC HER. This work therefore provides a quantitative understanding of the roles of PIRET and HET in boosting PEC activity.

3D-Printed Hydrogel Patches Embedded with Cu-Modified Liquid Metal Nanoparticles for Accelerated Wound Healing.

Wound healing is significantly challenged by resistant bacterial infections. Gallium-based liquid metal (LM) antibacterial agents show promise due to their non-inducement of resistance, though their efficacy remains limited. Here, we graft copper onto nano-LM surfaces via ultrasonication to create copper-modified LM nanoparticles (Cu-LMNPs) with enhanced antibacterial properties. Specific experiments suggest that Cu-LMNPs enhance antibacterial efficacy against ampicillin-resistant Escherichia coli (E. coli) and methicillin-resistant Staphylococcus aureus (MRSA) in vitro, achieving ≈100% antibacterial effectiveness. The remarkable antibacterial efficacy stems from the considerable increase in Cu2⁺ and Ga3⁺ concentrations. Further, the Cu-LMNPs and epidermal growth factors (EGF) are incorporated into the rheology-tunable hydrogels with excellent printability and biocompatibility for accelerating chronically infected wound healing. In vivo experiments demonstrate that the hydrogel patches effectively treated MRSA-infected wounds in mice. Sustained release of multiple ions and EGF promotes epithelial regeneration, collagen deposition, and neovascularization, making the wound markedly distinct from the control group and nearly fully healed within 10 days. Overall, this research presents a novel 3D-printed mesh hydrogel patch that not only combats bacterial infections but also accelerates wound healing.

MOF-Derived Hollow Fe/FeN/C Heterogeneous Composites for Broad-Band and Efficient Microwave Absorption.

The construction of hollow structures and the incorporation of metal nanoparticles have been shown to be two potential approaches to achieving high-performance microwave absorption. In this study, a hollow polyhedron material featuring an FeN/Fe-doped carbon matrix was synthesized by an acidification corrosion and pyrolysis strategy. The formation of heterojunctions, coupled with the design of hollow structures, significantly improved the dielectric loss capacity of the material. Furthermore, the incorporation of magnetic metal nanoparticles not only increased the magnetic loss but also enriched the loss mechanisms of the material, leading to an overall improvement in the magnetic loss. Under the synergistic effects of these factors, the material exhibited exceptional microwave absorption properties. In particular, at a material thickness of only 2.3 mm, the minimum reflection loss value of the FeN/Fe@HC nanocomposite reached -64.5 dB with an effective absorption bandwidth of 5.1 GHz. These results further highlight the importance of a hollow structure design and metal atom doping in improving microwave absorption performance.

Transformative potential of plant-based nanoparticles in cancer diagnosis and treatment: bridging traditional medicine and modern therapy.

Cancer is a primary global health concern, with an estimated 35.3 million cancer cases expected worldwide, representing a 76.6% increase in 2022, and 20 million by 2050, resulting from genetic mutation and environmental factors that cause uncontrolled cell growth. Other factors including smoking, unhealthy diets, physical inactivity, exposure to carcinogens, UV radiation, and aging increase DNA damage. Current cancer treatments like chemotherapy, radiation therapy, immunotherapy, and surgery are effective, but those have significant effects like lack of specificity, development of drug resistance, and significant side effects to healthy tissues. An advancement to conventional therapies is plant-based nanoparticles as transformative approaches in cancer diagnosis and treatment. These nanoparticles synthesized using plant bioactive compounds like flavonoids, alkaloids, polyphenols, and some metals-oxides like gold, silver, copper, zinc, etc. offer eco-friendly, cost-effective, and biocompatible alternatives. They enhance targeted drug delivery, allowing anticancer agents specifically to tumor cells, minimizing damage to health. Improves imaging techniques like MRI and fluorescence imaging, and helps early detection, cancer biomarkers, allowing for prompt intervention. Recent findings show that nanocarriers made from plant-based materials, such as polyphenols (curcumin, resveratrol) and plant-extracted metal nanoparticles (gold, silver), can improve drug stability and selectively target tumor cells. Plant-derived nanoparticles play a crucial role in cancer immunotherapy and nanovaccines. Biodegradable plant-based nanocarriers can deliver cancer vaccines, stimulating long-term immunity against tumors. Graphene oxide and gold nanoparticles synthesized from plant extracts can absorb near-infrared (NIR) light, generating heat to destroy cancer cells with minimal damage to surrounding tissues. This study discusses the types of plant-based nanoparticles like plant virus nanoparticles (TMV, PVX, CPMV), plant metallic nanoparticles (Au, Ag., Cu, Zn, Mg, Ca, and Mn), and flavonoid nanoparticles found in cancer treatment, their significant roles, chemotherapy-based nanomedicines available in the medical field, and a detailed vision of nanomaterial applications in cancer diagnosis, treatment, and targeted drug delivery.

Liquid metal nanoparticles for enhanced delivery of benzoporphyrin derivative in photodynamic cancer therapy.

Photodynamic therapy (PDT) is a targeted cancer treatment offering precise tumor ablation with minimal systemic toxicity. However, its clinical application is constrained by poor solubility, rapid clearance, and inadequate tumor accumulation of photosensitizers (PS). This study presents an innovative liquid metal nanoparticle (LMNP) platform, composed of gallium-indium eutectic alloy (EGaIn), engineered to address these drug delivery challenges in PDT. Using a one-step sonication process, EGaIn nanoparticles are synthesized and functionalized with folic acid (FA) for tumor-specific targeting, beta cyclodextrin (β-CD) for enhanced drug encapsulation, and benzoporphyrin derivative (BPD) as a PS. The inclusion of β-CD significantly improves the BPD loading capacity, achieving a three-fold enhancement (52% vs. 18%) while ensuring nanoparticle stability and sustained drug release. Covalent binding of FA and β-CD to the gallium oxide surface enables effective targeting and biocompatibility. Invitro analyses demonstrate potent PDT efficacy, even with reduced cellular uptake, underscoring the platform's ability to overcome intracellular delivery barriers. This LMNP-based nanoplatform addresses critical PDT limitations, such as suboptimal drug delivery and systemic toxicity, leveraging the unique chemical and physical properties of EGaIn nanoparticles. Its multifunctional design integrates targeted delivery, controlled release, and precise therapeutic activation, representing a promising advancement in the development of effective, personalized cancer treatment strategies.

Polymer Nanospheres Prepared by Metal Nanoparticles Initiation: Prospects for Application in Enhanced Oil Recovery

Polymer Nanospheres Prepared by Metal Nanoparticles Initiation: Prospects for Application in Enhanced Oil Recovery

Advances in Nanostructured Electrodes for Solid Oxide Cells by Infiltration or Exsolution

Solid oxide cells (SOCs) are highly efficient and versatile devices capable of utilizing a variety of fuels, presenting promising solutions for energy conversion and renewable resource utilization. There is an urgent need for the strategic design of robust and high-efficiency materials to enhance both conversion and energy efficiencies before SOCs can be applied for large-scale industrial production. Nanocomposite electrodes, especially those fabricated through infiltration and metal nanoparticle exsolution, have emerged as highly active electrocatalytic materials that significantly improve the performance and durability of SOCs. This review systematically summarizes and analyzes recent advances in the nanoscale architecture of electrode materials fabricated via common nanoengineering strategies, including infiltration and in situ exsolution, with applications in CO2/H2O reduction, hydrocarbon electrochemical oxidation, solid oxide fuel cells, and reversible operation. Finally, this review highlights existing bottlenecks and promising breakthroughs in common nanotechnologies, aiming to provide useful references for the rational design of nanomaterials for SOCs.

Smart nanoparticle delivery of cancer vaccines enhances tumor immune responses: a review

Cancer arises from the uncontrolled proliferation of tumor cells within the body. As the incidence of cancer continues to rise, its treatment has become a critical focus for clinicians. The body possesses a tumor immune surveillance mechanism designed to inhibit the proliferation of tumor cells. When tumor-associated mutant antigens appear on the cell surface, antigen-presenting cells, as dendritic cells, present these specific antigens to immune cells, such as T lymphocytes, thereby promoting an immune response and enhancing the cytotoxic effect on tumor cells. Concurrently, the immune system develops immune memory, akin to the response elicited by vaccination. While traditional diseases like tuberculosis and tetanus can be prevented and treated through vaccination, the development of cancer vaccines remains in its nascent stages. Tumor-specific antigens for cancer vaccines can originate from the patient’s own tumor cells or be generated through mutation. Thus, enhancing the presentation of tumor-specific antigens to immune cells is pivotal in anti-tumor immunotherapy. Advances in nanoscience offer novel approaches to tumor immunotherapy. Nanoparticles (NPs) engineered through nanotechnology have garnered significant attention due to their diverse, favorable, and stable properties. These NPs can effectively encapsulate chemotherapy drugs and proteins, facilitating targeted delivery in vivo. Common NPs carriers include liposomes, polymeric nanoparticles, and metal nanoparticles, among others. The development of intelligent NPs delivery systems can enhance efficient antigen presentation, thereby augmenting tumor immune responses. Tumor-specific antigens can be sourced from tumor cells or generated through mutation. In this review, we summarize current methodologies for obtaining various tumor-specific antigens and discuss how these antigens can be delivered to immune cells via different intelligent NPs to bolster anti-tumor immunity. Additionally, from a clinical translation perspective, we explore the challenges and opportunities associated with enhancing tumor immune responses through the smart NP delivery of cancer vaccines. We aim for this review to inspire new strategies in cancer treatment through the use of intelligent NPs and to advance research in cancer vaccines.

Synthesis and applications of Au-Ag bimetal impregnated layered manganese oxide nanocomposite

In present study, gold and silver metal nanoparticles were prepared and pillared on the manganese oxide octahedral molecular sieve type layered material. This method helps to stabilize the metal nanoparticles and for the synergetic catalytic effect of both manganese oxide and noble metal catalyst towards catalysis. Formation of layered manganese oxide in pure form and with pillaring was confirmed by XRD. Surface topology and chemical state were studied by SEM with EDS, TEM and XPS respectively. Batch studies have been conducted to evaluate the catalytic oxidative degradation of methylene blue dye using AuAg@LMO

ENHANCED PLASMONIC ACTIVITY IN AG-MODIFIED MnO2/SiO2 SPHERES FOR RAPID MITIGATION OF ANTIBIOTIC RESISTANCE

Ternary SiO2/MnO2–Ag composites were synthesized and evaluated as photocatalysts for the degradation of antibiotic Tetracycline (TC) in aqueous solution. Morphological and optical analyses demonstrated that MnO2 nanoparticles were efficiently tailored on the adsorbed sites of SiO2 spheres, while plasmonic metallic silver nanoparticles (Ag NPs) were coated on the surface of the SiO2/MnO2 composite. The SiO2/MnO2–Ag ternary composition, as obtained, exhibited remarkable photocatalytic activity in the degradation of TC (91.3%) antibiotic, surpassing the performance of individual SiO2, MnO2, and SiO2/MnO2 catalysts. This higher photocatalytic efficiency is primarily attributed to two key factors: enhanced photo-absorption capabilities facilitated by the presence of Ag nanoparticles, and the substantial mitigation of photoinduced electron and hole recombination through efficient charge transfer at the Schottky junction. SiO2 plays a pivotal role by acting as a template that accelerates the separation of electron–hole pairs, while Ag metal serves as an electron sink, thereby bolstering interfacial charge transfer.

Predicting Adhesion Energies of Late Transition Metal Nanoparticles to Oxide Support Surfaces Using Oxide Reducibility and Metal Oxophilicity: Toward Predicting Catalyst Performance

Predicting Adhesion Energies of Late Transition Metal Nanoparticles to Oxide Support Surfaces Using Oxide Reducibility and Metal Oxophilicity: Toward Predicting Catalyst Performance

Comparative study of Raman modes active, emission bands and thermal features of GS Α-Al2O3 NP’s

This work, focuses on spectroscopic features such as PL and Raman and thermal analysis such (TGA –DSC) for the nanoparticles of aluminium oxide (GS α-Al2O3) synthesizes by two plant solutions (leaves(S1) and phloem(S2)) at room temperature. In different reactions, plant extracts are mixed with metal precursor solutions, Various reactions are carried out with metal precursor solutions when plant extracts are combined with them and biomolecules are responsible for reducing metal ions and capping the bio-reduced metal nanoparticles synthesized by using plant extract. As a result, calcination of the products of powder alumna at 1800 ͦC found that the phase was α-AL2O3, analysis of PL was achieved when excited of two samples (S1 and S2) by different wavelengths at 200 nm,250nm and 300 nm, it gave at λ ex =300nm, three peaks of emission at 295 nm, 350 nm 590 for S1 and 300 nm 360 nm 590nm for S2 respectively at the Eg values 4.2,2.9,2.1eV and 4.1eV and 3.4,2.1eV from UV to the yellow range, results in thermal analysis notice that rapidly loss in the weight to reach for the stable phase of α-Al2O3. Raman active modes have seven actives for both prepared samples S1 and S2, these samples of Al2O3 can be applied in highperformance heat and dye degradation.

Evolution of the Phase Transition in the Nematic Phase of a Liquid Crystal Doped with Metallic Nanoparticles

Polymer-dispersed liquid crystal (PDLC) films containing nanosized droplets of nematic liquid crystal (NLC) with metallic nanoparticle (NP) additives were investigated for potential use in display devices. Polarizing optical microscopy (POM) and differential scanning calorimetry (DSC) methods showed that PDLC films with low concentrations of NPs significantly alter the optical properties (transmission coefficient, threshold voltage, contrast and absorption coefficients) of the materials under study. It was found that, with a constant UV irradiation intensity, the dye concentration can be optimized to ensure uniform droplet size, higher light transmission, and increased contrast coefficient. Using the Beer-Lambert equation, absorption and extinction coefficients were obtained by measuring the light transmission of PDLC films. It was discovered that the liquid crystal droplets in the PDLC films predominantly adopt a bipolar configuration. A higher content of metallic nanoparticles leads to a decrease in the clearing temperature and a reduction in light transmission due to the lowered order parameter caused by thermal fluctuations. Numerical calculation results showed that the maximum contrast coefficient for PDLC films with nanoparticle content is 2.55 times higher than the minimum contrast coefficient of the films in their initial state. Possible mechanisms for the implementation of these results have been proposed for the creation of flexible liquid crystal display elements used in environmentally friendly technologies.

Cancer nanomedicine from a clinician-scientist perspective: Lessons and prospects.

The nanomedicine field has progressed enormously in the last couple of decades. From a loose group of liposomologists, polymer scientists, chemical engineers, and experts in metal nanoparticles, mesoporous silica, and other nanomaterials, the field has gradually consolidated and has generated vast amounts of research and clinical data, but, until the development of lipid nanoparticle (LNP)-based vaccinations for Covid-19, has remained with low visibility in the clinic. Applications in the cancer field are the most frequently sought projects in nanomedicine. For the last 45 years, my clinical career has mingled with my research career focusing on ways to formulate drugs in liposomes to improve their safety and efficacy in cancer therapy. In this review, I will discuss my contribution to the development of pegylated liposomal doxorubicin and other cancer nanomedicines from my privileged position as a clinician and scientist.

Antibacterial properties of silver and gold nanoparticles synthesized using Cannabis sativa waste extract against Pseudomonas aeruginosa

AimsThe study aimed to explore the sustainable synthesis of metal nanoparticles using a green and eco-friendly resource. Specifically, it investigated the utilization of Cannabis sativa waste extract for the production of gold and silver nanoparticles, focusing on their antimicrobial activity against gram-negative bacteria, particularly Pseudomonas aeruginosa strains, which are significant in nosocomial infections.MethodsCannabis sativa waste extract was employed to synthesize gold and silver nanoparticles through a green synthesis approach. The produced nanoparticles were characterized using transmission electron microscopy (TEM), atomic absorption spectrometry (AAS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The antimicrobial efficacy of the synthesized nanoparticles was assessed through their minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and minimal biofilm inhibitory concentration (MBIC) against Pseudomonas aeruginosa, utilizing a microcultivation device, solid medium cultivation, and a metabolic activity assay in a polystyrene microtiter plate, respectively.ResultsThe TEM analysis revealed the size and morphology of the nanoparticles, while AAS confirmed their concentration. XRD provided insights into the crystalline structure, and FTIR analysis identified the molecular structure of the nanoparticle’s stabilizing layer. The synthesized nanoparticles showed significant antimicrobial activity against Pseudomonas aeruginosa, with determined MIC, MBC, and MBIC values of produced silver nanoparticles, showcasing their potential as effective antimicrobial agents.ConclusionsThis study successfully demonstrated the synthesis of silver and gold nanoparticles using Cannabis sativa waste extract and highlighted their potent antimicrobial properties. It underscores the potential of utilizing plant waste extracts in sustainable nanomaterial synthesis and contributes to the fields of green nanotechnology and waste valorization within the circular economy. The findings also offer valuable insights into developing natural waste source-based antimicrobial agents.

Remove the innermost atom of a magnetic multi-shell gold nanoparticle for near-unity conversion of CO2 to CO.

Few reports on paramagnetic metal nanoparticles with atomic precision and their difficult tailoring retard the insightful investigation of metal nanoparticle paramagnetism. Herein, we introduced a thiol-iodine mixture ligand-protecting strategy to successfully synthesize multi-shell paramagnetic [Au127I4(TBBT)48 (I: iodine, TBBT: 4-tert-butylphenylthiolate)]. The innermost Au atom was successfully removed via thiol induction without altering the structure framework to produce diamagnetic Au126I4(TBBT)48 with local ligand arrangement changed (butterfly effect), which could be further transformed into paramagnetic [Au126I4(TBBT)48]+ via hydrogen peroxide oxidation. The spin populations of both paramagnetic nanoparticles are more densely distributed on surface iodine than sulfur. Diamagnetic Au126I4(TBBT)48 exhibited a Faradaic efficiency of ~100% at -0.57volt during the electrocatalytic reduction of carbon dioxide to carbon monoxide, while paramagnetic Au127I4(TBBT)48 and [Au126I4(TBBT)48]+ exhibited the maximum Faradaic efficiency of 87% at -0.67volt and 90% at -0.57volt, respectively, indicating the spin-catalytic activity correlation.

Plasmonic-Hydrogel Hybrid Biomaterials via In Situ Seeded Growth.

The combination of hydrogels and functional plasmonic metal nanoparticles affords the development of unique hybrid systems, such as actuators, biosensors, and drug delivery systems, among others. Being typically prepared in colloidal suspension, incorporating shape-controlled plasmonic nanoparticles on polymer substrates typically requires lengthy processes involving synthesis, washing, and self-assembly. We report an alternative, robust in situ seed-mediated growth method, whereby either isotropic or anisotropic Au and Ag nanoparticles can be prepared directly on gelatin-based hydrogels, taking advantage of the polymer's native chemical functionalities. In-depth characterization of gold precursor - polymer interactions enabled the rational growth of branched gold nanoparticles on biocompatible hydrogels with different physicochemical properties. In situ seeded growth circumvents traditional limitations imposed by the need of colloidal stability, thereby enabling gold nanoparticle synthesis under surfactant-free conditions and in high ionic strength solutions, thus enhancing their suitability for applications with live cells. This method can be expanded to create libraries of hybrid plasmonic materials with potential impact in the fabrication of functional 3D cell culture substrates, as well as biological and chemical sensors.

Plasmonic‐Hydrogel Hybrid Biomaterials via In Situ Seeded Growth

The combination of hydrogels and functional plasmonic metal nanoparticles affords the development of unique hybrid systems, such as actuators, biosensors, and drug delivery systems, among others. Being typically prepared in colloidal suspension, incorporating shape‐controlled plasmonic nanoparticles on polymer substrates typically requires lengthy processes involving synthesis, washing, and self‐assembly. We report an alternative, robust in situ seed‐mediated growth method, whereby either isotropic or anisotropic Au and Ag nanoparticles can be prepared directly on gelatin‐based hydrogels, taking advantage of the polymer’s native chemical functionalities. In‐depth characterization of gold precursor ‐ polymer interactions enabled the rational growth of branched gold nanoparticles on biocompatible hydrogels with different physicochemical properties. In situ seeded growth circumvents traditional limitations imposed by the need of colloidal stability, thereby enabling gold nanoparticle synthesis under surfactant‐free conditions and in high ionic strength solutions, thus enhancing their suitability for applications with live cells. This method can be expanded to create libraries of hybrid plasmonic materials with potential impact in the fabrication of functional 3D cell culture substrates, as well as biological and chemical sensors.

Enhanced electrocatalytic performance of carbon-coated NiCoO2/NiCo composites for efficient water splitting

The urgent need for sustainable energy conversion technologies has propelled the development of efficient and cost-effective electrocatalysts for water splitting. In this study, we synthesize carbon-coated NiCoO2/NiCo@C composites through the calcination of CoNi Prussian Blue Analogues nanocubes, aiming to enhance the electrocatalytic performance for both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Our findings demonstrate that the NiCoO2/NiCo@C composites exhibit outstanding catalytic activity, achieving low overpotentials of 329 mV for OER and 61.9 mV for HER at a current density of 10 mA cm−2, with robust stability under prolonged operational conditions. The enhanced activity is attributed to the large interface area and high density of exposed active sites facilitated by the unique heterojunction structure of NiCoO2/NiCo particles embedded in carbon frameworks and nanotubes. This architecture not only prevents the agglomeration of metal nanoparticles but also promotes efficient electron and proton transfer, significantly boosting electrochemical performance. This study introduces a promising approach for designing high-performance, cost-effective electrocatalysts, paving the way for their application in industrial water electrolysis.

Numerical study of higher-order chemical reactions and the Dofour-Soret effect on radiative hybrid nanofluid flow over a stretching curve surface

Curve-shaped stretching sheets have many notable applications in foam bubbles, molecular films, aerosol drops, and soap films. Hybrid nanofluids exhibit effective heat transmission due to their dual metallic nanoparticles within the base fluid and have a wide range of potential uses. In this article, we investigated the Dufour and Soret effects on hybrid nanofluid flow over a permeable nonlinear stretching curve surface with higher-order chemical reactions and nonlinear solar radiation. We considered the aluminium oxide ( ) and graphene as nanoparticles and suspended them in ethylene glycol. The non-linear leading equations are converted into dimensionless ordinary linear equations (ODEs) by appropriate similarity transformation. The RK-4 shooting method solves the transformed equations, while Mapple-21 simulates the results. Features of the fluid flow are investigated for various parameters, and the findings are displayed using diagrams and charts. The most important findings of this research are the effects of several parameters on the velocity and temperature distribution, as well as the engineering quantities. The value of skin friction was reduced by 63.92% for suction and 64.34% for injection when the radius of curvature increased from 0.2 to 0.6. Additionally, the Nusselt number increased at a rate of 43.39% for suction and 72.72% for injection near the surface as the radiation parameter increased from 0.2 to 0.6. The increasing rate of the Sherwood number is 53.65% for injection, and it drops off by 82.15% for suction when the Soret number increases from 1 to 5.