Multicomponent Nanoparticles Research Articles

Surface oxygenation of multicomponent nanoparticles toward active and stable oxidation catalysts

The need for active and stable oxidation catalysts is driven by the demands in production of valuable chemicals, remediation of hydrocarbon pollutants and energy sustainability. Traditional approaches focus on oxygen-activating oxides as support which provides the oxygen activation at the catalyst-support peripheral interface. Here we report a new approach to oxidation catalysts for total oxidation of hydrocarbons (e.g., propane) by surface oxygenation of platinum (Pt)-alloyed multicomponent nanoparticles (e.g., platinum-nickel cobalt (Pt–NiCo)). The in-situ/operando time-resolved studies, including high-energy synchrotron X-ray diffraction and diffuse reflectance infrared Fourier transform spectroscopy, demonstrate the formation of oxygenated Pt–NiOCoO surface layer and disordered ternary alloy core. The results reveal largely-irregular oscillatory kinetics associated with the dynamic lattice expansion/shrinking, ordering/disordering, and formation of surface-oxygenated sites and intermediates. The catalytic synergy is responsible for reduction of the oxidation temperature by ~100 °C and the high stability under 800 °C hydrothermal aging in comparison with Pt, and may represent a paradigm shift in the design of self-supported catalysts.

Single-phase Gd0.2La0.2Ce0.2Hf0.2Zr0.2O2 and Gd0.2La0.2Y0.2Hf0.2Zr0.2O2 nanoparticles as efficient photocatalysts for the reduction of Cr(VI) and degradation of methylene blue dye

We report for the first time the use of noble metal-free multi-component equiatomic oxide as photocatalysts with excellent performance for natural sunlight driven degradation of Cr(VI) and methylene blue dye. The multi-component oxide nanoparticles with a composition Gd0.2La0.2Ce0.2Hf0.2Zr0.2O2 and Gd0.2La0.2Y0.2Hf0.2Zr0.2O2 were synthesized by simple co-precipitation followed by peptization in acid to obtain nanoparticle sol and calcined at 500 °C. The nanopowders were characterized by x-ray diffraction (XRD), UV–Visible spectroscopy (UV–Vis), and high-resolution transmission electron microscopy (HRTEM). The complete (∼100%) reduction of Cr(VI) to Cr(III) was observed after 90 and 100 min for the calcined Gd0.2La0.2Ce0.2Hf0.2Zr0.2O2 and Gd0.2La0.2Y0.2Hf0.2Zr0.2O2 respectively, under exposure to natural sunlight. In addition, 70% degradation of methylene blue is observed in 180 min. The effective photocatalytic activity of multi-component oxides can be attributed to their unique composition containing five components in equimolar amounts. The role of oxygen vacancies in photocatalytic reduction of Cr(VI) and the degradation of methylene blue is also discussed.

Abstract 2618: Tumor multicomponent targeting nanoparticle for synergistic killing of drug resistant renal cell carcinoma

Abstract Targeted therapy in renal cell carcinoma (RCC) has limited clinical response due to the development of drug resistance. Drug resistance can be acquired through multiple pathways including, impairment of apoptosis, overexpression of hypoxia promoting carbonic anhydrase 9 (CA9), and infiltration of folate receptor (FR) positive tumorigenic macrophages. Our hypothesis was to overcome the drug resistance by developing a tumor stimuli-responsive nanoparticle (NP) that can carry combination drugs, such as Cabozantinib (CB) and CFM 4.16 in RCC. The rationale of choosing the CB in combination with CFM4.16 was to induce synergistic anti-RCC effect by modulating the multiple tumor survival pathways, such as caspase 3, Akt/p-Akt, MET. One of the major challenges of the CB and CFM4.16 combination therapy is their poor water solubility and limited targetability to cancer. Thus, we came up with a smart strategy of developing dual folate receptor (FR) and carbonic anhydrase-9 (CA9) biomarker directed nanoparticles that can target the tumor stroma and hypoxia of RCC, respectively. In this proof of concept study, we synthesized SMA-TPGS and SMA polymer (PL) comprising of FR and CA9 dual targeting ligand, namely, FR-CA9-OL using reagent free ‘click' chemistry. FR-CA9-PL was encapsulated either with CFM4.16 or with CB to obtain nanoparticles, called FR-CA9-C4.16 and FR-CA9-CB respectively. The nanoparticles were prepared by using a co-solvent dialysis method that resulted in small-particle size with a range of 80-100 nm diameter, narrow polydispersity index of ∼ 0.15 and high drug loading of 30% (wt./wt.). The homogenous and high drug loading characteristics of nanoparticles are optimal for penetrating hypoxia of RCC. The IC50 of FR-CA9-C4.16 was improved by 60-fold as compared to CFM4.16 treatment and IC50 of FR-CA9-CB is improved by 16-fold compared to CB treatment in aggressive Everolimus-resistant (Evr-res) A498 RCC cells. The combination of FR-CA9-C4.16 with FR-CA9-CB demonstrated synergistic killing of Evr-res-A498 with CI value 0.1-0.5. The signature characteristic and superior anticancer effect of nanoparticles in Evr-resistant RCC provide a worthwhile strategy for overcoming drug resistance in RCC. Citation Format: Kushal Vanamala, Samaresh Sau, Shivani Naik, Arun K. Rishi, Arun Iyer. Tumor multicomponent targeting nanoparticle for synergistic killing of drug resistant renal cell carcinoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2618.

Multicomponent 3d Transition-Metal Nanoparticles as Catalysts Free of Pd, Pt, or Rh for Automotive Three-Way Catalytic Converters

Multicomponent 3d transition metal nanoparticles supported on Al2O3 were prepared using a complex polymerization process and a post H2-reduction treatment at 900 °C. Catalysts in a binary system we...

PtCu/C Materials Doped with Different Amounts of Gold as the Catalysts of Oxygen Electroreduction and Methanol Electrooxidation

The effect of the amount of gold used as the dopant of PtCu nanoparticles on the structure of PtCuAu/Cu catalysts and their activity in the reactions of oxygen reduction and methanol electrooxidation is studied. The PtCuAu/C materials containing from 3 to 20% of gold are prepared by galvanic displacement of copper atoms by gold atoms on the surface of already prepared PtCu nanoparticles. The addition of 5 at % Au to the composition of nanoparticles doubles their activity in the methanol oxidation and increases their activity in the oxygen reduction by a factor of 1.7 as compared with the commercial Pt/C material JM40. This study confirms that multicomponent platinum-containing nanoparticles supported by a highly disperse carbon material and having gold atoms deposited on their surface show promise as the efficient catalysts for the methanol fuel cells. In contrast, the materials containing 10 at % Au and more are characterized by the presence of gold nanoparticles on the carbon support surface and exhibit the lower catalytic activity as compared with those containing less amounts of gold.

A multi-component system for urea electrooxidation: Ir3Sn nanoparticles loading on Iron- and Nitrogen- codoped composite carbon support

Multi-component system is a good strategy in attaining highly efficient electrocatalyst. In this study, through combining two aspects of multi-component alloy and composite support, a multi-component system of Ir3Sn/FeNC electrocatalyst is obtained for urea electrooxidation reaction. With a series of the characterizations, the heterogeneous structure of Ir3Sn/FeNC electrocatalyst, which consists of multi-component Ir3Sn alloy nanoparticles and composite FeNC support, is identified. The electrochemical results show that the Ir3Sn/FeNC exhibits the best electrocatalytic performance for urea oxidation with the highest UOR peak current density (0.157 A mg−1) and long-time current density (0.013 A mg−1 after 5000 s) when compared with Ir3Sn/C, Ir/FeNC and Ir/C electrocatalysts. This multi-component Ir3Sn/FeNC catalyst presents great potential for the development of urea fuel cells.

Physics-informed neural networks for inverse problems in nano-optics and metamaterials

In this paper, we employ the emerging paradigm of physics-informed neural networks (PINNs) for the solution of representative inverse scattering problems in photonic metamaterials and nano-optics technologies. In particular, we successfully apply mesh-free PINNs to the difficult task of retrieving the effective permittivity parameters of a number of finite-size scattering systems that involve many interacting nanostructures as well as multi-component nanoparticles. Our methodology is fully validated by numerical simulations based on the finite element method (FEM). The development of physics-informed deep learning techniques for inverse scattering can enable the design of novel functional nanostructures and significantly broaden the design space of metamaterials by naturally accounting for radiation and finite-size effects beyond the limitations of traditional effective medium theories.

Towards superior mechanical properties of hetero-structured high-entropy alloys via engineering multicomponent intermetallic nanoparticles

Dual-phase high-entropy alloys strengthened by multicomponent intermetallic nanoparticles represent a unique class of hetero-structured materials with potentially superior mechanical properties for structural applications. Due to the multicomponent chemistries of both nanoparticles and the matrix, as well as the coherent interfaces between them, these alloys can possess excellent strength-ductility combinations over a wide temperature range. This brief viewpoint article gives an overview of the major developments achieved recently. Advantages over other classes of metallic materials as well as limitations in this field are also carefully discussed. The results provide new insights into the development of high-performance structural materials via multicomponent-nanoparticle engineering.

Electrospinning synthesis of transition metal alloy nanoparticles encapsulated in nitrogen-doped carbon layers as an advanced bifunctional oxygen electrode

A universal and scalable electrospinning method was developed to produce uniform multicomponent alloy nanoparticles encapsulated in N doped thin carbon layers as bifunctional catalysts for OER and ORR.

Multi-component (Ag-Au-Cu-Pd-Pt) alloy nanoparticle-decorated p-type 2D-molybdenum disulfide (MoS2) for enhanced hydrogen sensing.

Molybdenum disulfide (MoS2) has emerged as a promising material for the development of efficient sensors. Here, we have exfoliated and decorated MoS2 flakes with the novel, single-phase multi-component silver-gold-copper-palladium-platinum (Ag-Au-Cu-Pd-Pt) alloy nanoparticles, popularly named High Entropy Alloy (HEA) nanoparticles, using facile and scalable low-temperature grinding, followed by the sonochemical method. It was found that the decoration of HEA nanoparticles imparts the surface-enhanced Raman scattering effect and reduction in the work function of the material from 4.9 to 4.75 eV as measured by UV photoelectron spectroscopy. This change in the work function resulted in a Schottky barrier between the gold contact and HEA decorated MoS2 flakes as a result of drastic changes in the surface chemical non-stoichiometry. The response to hydrogen gas was studied at temperatures in the range of 30 to 100 °C, and it showed an unusual p-type nature due to surface-adsorbed oxygen species. The nanoscale junction formed between HEA and MoS2 showed a ten-time increase in the response towards hydrogen gas at 80 °C. The experimental observations have been explained with DFT simulation showing more favourable hydrogen adsorption on HEA-decorated MoS2 resulting in an enhanced response.

Exploiting kinetics for assembly of multicomponent nanoparticle networks with programmable control of heterogeneity.

Kinetic control of metal chalcogenide nanoparticle oxidative assembly is realized by varying the redox potential of the chalcogenide, structure (wurtzite vs. zinc blende), and ligand chain length. This knowledge is exploited to form two-component (ZnS + CdSe) hybrid aerogels with minimal heterobonding (phase-segregated) or maximal heterobonding (intimately mixed).

Multicomponent Plasmonic Nanoparticles: From Heterostructured Nanoparticles to Colloidal Composite Nanostructures.

Plasmonic nanostructures possessing unique and versatile optoelectronic properties have been vastly investigated over the past decade. However, the full potential of plasmonic nanostructure has not yet been fully exploited, particularly with single-component homogeneous structures with monotonic properties, and the addition of new components for making multicomponent nanoparticles may lead to new-yet-unexpected or improved properties. Here we define the term "multi-component nanoparticles" as hybrid structures composed of two or more condensed nanoscale domains with distinctive material compositions, shapes, or sizes. We reviewed and discussed the designing principles and synthetic strategies to efficiently combine multiple components to form hybrid nanoparticles with a new or improved plasmonic functionality. In particular, it has been quite challenging to precisely synthesize widely diverse multicomponent plasmonic structures, limiting realization of the full potential of plasmonic heterostructures. To address this challenge, several synthetic approaches have been reported to form a variety of different multicomponent plasmonic nanoparticles, mainly based on heterogeneous nucleation, atomic replacements, adsorption on supports, and biomolecule-mediated assemblies. In addition, the unique and synergistic features of multicomponent plasmonic nanoparticles, such as combination of pristine material properties, finely tuned plasmon resonance and coupling, enhanced light-matter interactions, geometry-induced polarization, and plasmon-induced energy and charge transfer across the heterointerface, were reported. In this review, we comprehensively summarize the latest advances on state-of-art synthetic strategies, unique properties, and promising applications of multicomponent plasmonic nanoparticles. These plasmonic nanoparticles including heterostructured nanoparticles and composite nanostructures are prepared by direct synthesis and physical force- or biomolecule-mediated assembly, which hold tremendous potential for plasmon-mediated energy transfer, magnetic plasmonics, metamolecules, and nanobiotechnology.

Targeted photodynamic therapy treatment of in vitro A375 metastatic melanoma cells.

Metastatic Melanoma (MM) is a deadly form of skin cancer and many photodynamic therapy (PDT) studies have noted limitations in relation to effective photosensitizer (PS) drug uptake in tumors. The focus of this study was to develop a PS multicomponent nanoparticle drug conjugate carrier system which specifically targets MM cells via biomarkers to actively enhance PS delivery and so improve MM PDT. An antibody-metallated phthalocyanine-polyethylene glycol-gold nanoparticle drug conjugate, was successfully synthesized and characterized. PS active drug targeting PDT experiments at 673 nm were conducted within in vitro cultured MM. Results noted that this drug conjugate enhanced the PDT treatment of MM, through improved subcellular localization of the PS, as well as noted significantly improved cytotoxic and late apoptotic cellular death in cells. The results from this study demonstrate that through the bio-active antibody PS drug targeting of MM, the efficacy of PDT treatment for this cancer can be enhanced.

Treatment of glioblastoma using multicomponent silica nanoparticles.

Glioblastomas (GBMs) remain highly lethal. This partially stems from the presence of brain tumor initiating cells (BTICs), a highly plastic cellular subpopulation that is resistant to current therapies. In addition to resistance, the blood-brain barrier limits the penetration of most drugs into GBMs. To effectively deliver a BTIC-specific inhibitor to brain tumors, we developed a multicomponent nanoparticle, termed Fe@MSN, which contains a mesoporous silica shell and an iron oxide core. Fibronectin-targeting ligands directed the nanoparticle to the near-perivascular areas of GBM. After Fe@MSN particles deposited in the tumor, an external low-power radiofrequency (RF) field triggered rapid drug release due to mechanical tumbling of the particle resulting in penetration of high amounts of drug across the blood-brain tumor interface and widespread drug delivery into the GBM. We loaded the nanoparticle with the drug 1400W, which is a potent inhibitor of the inducible nitric oxide synthase (iNOS). It has been shown that iNOS is preferentially expressed in BTICs and is required for their maintenance. Using the 1400W-loaded Fe@MSN and RF-triggered release, in vivo studies indicated that the treatment disrupted the BTIC population in hypoxic niches, suppressed tumor growth and significantly increased survival in BTIC-derived GBM xenografts.

Magnetron Sputtering of Polymeric Targets: From Thin Films to Heterogeneous Metal/Plasma Polymer Nanoparticles.

Magnetron sputtering is a well-known technique that is commonly used for the deposition of thin compact films. However, as was shown in the 1990s, when sputtering is performed at pressures high enough to trigger volume nucleation/condensation of the supersaturated vapor generated by the magnetron, various kinds of nanoparticles may also be produced. This finding gave rise to the rapid development of magnetron-based gas aggregation sources. Such systems were successfully used for the production of single material nanoparticles from metals, metal oxides, and plasma polymers. In addition, the growing interest in multi-component heterogeneous nanoparticles has led to the design of novel systems for the gas-phase synthesis of such nanomaterials, including metal/plasma polymer nanoparticles. In this featured article, we briefly summarized the principles of the basis of gas-phase nanoparticles production and highlighted recent progress made in the field of the fabrication of multi-component nanoparticles. We then introduced a gas aggregation source of plasma polymer nanoparticles that utilized radio frequency magnetron sputtering of a polymeric target with an emphasis on the key features of this kind of source. Finally, we presented and discussed three strategies suitable for the generation of metal/plasma polymer multi-core@shell or core-satellite nanoparticles: the use of composite targets, a multi-magnetron approach, and in-flight coating of plasma polymer nanoparticles by metal.

RAFT Dispersion Polymerization in the Presence of Block Copolymer Nanoparticles and Synthesis of Multicomponent Block Copolymer Nanoassemblies

Multicomponent block copolymer nanoassemblies are constructed by two or more than two block copolymers. Herein, multicomponent block copolymer nanoparticles constructed with poly(4-vinylpyridine)-b...

Rationally Designed PdAuCu Ternary Alloy Nanoparticles for Intrinsically Deactivation-Resistant Ultrafast Plasmonic Hydrogen Sensing.

Hydrogen sensors are a prerequisite for the implementation of a hydrogen economy due to the high flammability of hydrogen-air mixtures. They are to comply with the increasingly stringent requirements set by stakeholders, such as the automotive industry and manufacturers of hydrogen safety systems, where sensor deactivation is a severe but widely unaddressed problem. In response, we report intrinsically deactivation-resistant nanoplasmonic hydrogen sensors enabled by a rationally designed ternary PdAuCu alloy nanomaterial, which combines the identified best intrinsic attributes of the constituent binary Pd alloys. This way, we achieve extraordinary hydrogen sensing metrics in synthetic air and poisoning gas background, simulating real application conditions. Specifically, we find a detection limit in the low ppm range, hysteresis-free response over 5 orders of magnitude hydrogen pressure, subsecond response time at room temperature, long-term stability, and, as the key, excellent resistance to deactivating species like carbon monoxide, notably without application of any protective coatings. This constitutes an important step forward for optical hydrogen sensor technology, as it enables application under demanding conditions and provides a blueprint for further material and performance optimization by combining and concerting intrinsic material assets in multicomponent nanoparticles. In a wider context, our findings highlight the potential of rational materials design through alloying of multiple elements for gas sensor development, as well as the potential of engineered metal alloy nanoparticles in nanoplasmonics and catalysis.

Flame-synthesized nickel-silver nanoparticle inks provide high conductivity without sintering

A new concept for the synthesis of conductive metal nanoparticle inks (nano-inks) is introduced using a one-step continuous flame-based process. Bimetallic nickel (Ni)-silver (Ag) nanopowders are simultaneously produced and functionalized in a High Temperature Reducing Jet (HTRJ) reactor. The HTRJ process allows rapid aerosol (gas phase) formation of multicomponent metal nanoparticles with relatively high production rates from low-cost metal precursors. Octylamine, a volatile aliphatic amine, is sprayed into the reactor effluent after the particle formation zone to cap nanoparticles as they form. Ni-Ag Functionalized Nano Powders (FNPs) were characterized and compared with Bare Nano Powders (BNPs) to verify that in situ ligand attachment was successful. Nano-inks were prepared by dispersing FNPs in an organic solvent. Conductive films were fabricated using different nano-ink compositions starting from pure Ni to 50 wt% Ni. With the use of a small capping agent, films containing 50 wt% (65 at%) Ni provide an electrical conductivity of 5.14 × 104 S m−1 without any post-processing. Conductivity increased to 4.22 × 105 S m−1 after thermal annealing in an inert environment. These sintering-free bimetallic conductive nanoparticles can be used as a lower cost replacement for current silver inks for single-step printing of conductive traces without post-processing.

Insights into the morphology of multicomponent organic and inorganic aerosols from molecular dynamics simulations

Abstract. We explore the morphologies of multicomponent nanoparticles through atomistic molecular dynamics simulations under atmospherically relevant conditions. The particles investigated consist of both organic (cis-pinonic acid – CPA, 3-methyl-1,2,3-butanetricarboxylic acid – MBTCA, n-C20H42, n-C24H50, n-C30H62 or mixtures thereof) and inorganic (sulfate, ammonium and water) compounds. The effects of relative humidity, organic mass content and type of organic compound present in the nanoparticle are investigated. Phase separation is predicted for almost all simulated nanoparticles either between organics and inorganics or between hydrophobic and hydrophilic constituents. For oxygenated organics, our simulations predict an enrichment of the nanoparticle surface in organics, often in the form of islands depending on the level of humidity and organic mass fraction, giving rise to core–shell structures. In several cases the organics separate from the inorganics, especially from the ions. For particles containing water-insoluble linear alkanes, separate hydrophobic and hydrophilic domains are predicted to develop. The surface partitioning of organics is enhanced as the humidity increases. The presence of organics in the interior of the nanoparticle increases as their overall mass fraction in the nanoparticle increases, but this also depends on the humidity conditions. Apart from the organics–inorganics and hydrophobics–hydrophilics separation, our simulations predict a third type of separation (layering) between CPA and MBTCA molecules under certain conditions.

Simultaneous separation of small interfering RNA and lipids using ion-pair reversed-phase liquid chromatography

RNA interference offers a novel approach for the development of new therapeutics for targets that are otherwise “undruggable” using traditional modalities. The safety and efficacy of siRNA-based therapy mainly rely on lipid or polymer-based nanocarriers to overcome inherent barriers to a systemic delivery of siRNA. A multicomponent lipid nanoparticle (LNP) system is a promising delivery platform, typically consisting of a cationic lipid, phospholipid, PEG-containing short-chain lipid, and cholesterol. Characterization and chemical analysis of the LNP formulation is important to assure drug product stability, a key consideration for chemistry, manufacturing and control strategy. Here we report an ion-pair reversed phase UHPLC method capable of simultaneously separating both siRNA and functional lipids in LNPs with a minimal retention gap for two classes of biologically essential yet chemically distinct molecules. Key chromatographic parameters critical to the separation are discussed, including the structure of the ion-pair agent, stationary phase chemistry, column temperature and an organic additive. The results showed that the retention time of siRNA is tunable by using various ion-pair reagents. The retention factor of the siRNA exhibited a first order relationship with the number of carbons in the alkyl chain of the ion-pair reagents. In contrast, the type of ion-pair reagent has no significant impact on the separation of phospholipids. Separations using a BEH phenyl column and dibutylammonium acetate as the ion-pair reagent showed satisfactory selectivity for a range of double-stranded siRNAs and phospholipids, key components for lipid nanoparticle formulations. Furthermore, the method was applied to the separation of an experimental LNP formulation, demonstrating good selectivity for siRNA, functional lipids and their potential degradation products.