Mesoporous metallic cells: design of uniformly sized hollow mesoporous Pt-Ru particles with tunable shell thicknesses

pH-Responsive, Self-Assembled Ruthenium Nanodrug: Dual Impact on Lysosomes and DNA for Synergistic Chemotherapy and Immunogenic Cell Death

Several DNA-damaging antitumor agents, including ruthenium complexes, induce immunogenic cell death (ICD). In this study, an arginyl-glycyl-aspartic acid (RGD) peptide-modified carboline ruthenium complex (KS-Ru) is synthesized as a chemotherapeutic nanodrug and an ICD inducer. The RGD peptide, an integrin ligand, provides tumor-specific targeting and promotes self-assembly of the KS-Ru complex. The pH-responsive self-assembly is assessed through transmission and scanning electron microscopy. Additionally, in vitro cytotoxic activity and anti-metastasis ability are evaluated using MTT and Transwell assays, respectively, along with cellular immunofluorescence staining and imaging flow cytometry. The ability of the complex to inhibit primary tumor formation and lung metastasis in vivo is evaluated using Lewis lung cancer and A549 xenograft models. Furthermore, the tumor immune microenvironment is evaluated using single-cell flow mass cytometry. KS-Ru translocates to the nucleus, causing DNA damage and inducing ICD. Within the lysosomes, KS-Ru self-assembled into nanoflowers, leading to lysosomal swelling and apoptosis. Notably, the as-synthesized pH-dependent ruthenium nanomedicine achieves dual functionality-chemotherapy and immunotherapy. Moreover, the pH-responsive self-assembly of KS-Ru enables simultaneous mechanisms in the lysosome and nucleus, thereby lowering the likelihood of drug resistance. This study provides valuable insight for the design of novel ruthenium-based nanoantitumor drugs.

Mesoporous Metal Nanomaterials: Developments and Electrocatalytic Applications

Mesoporous metal nanomaterials (MPMNs) are pivotal in nanotechnology, especially in electrochemical applications, due to their unique structure. Unlike traditional nanomaterials, MPMNs possess hierarchical and mesoporous characteristics, providing more active sites for improved mass and electron transfer. This distinctive composition offers dual benefits, enhancing activity, stability, and selectivity for specific reactions. The intricate architecture, featuring interconnected pores, amplifies surface area, ensuring efficient use of active sites and boosting reactivity in electrocatalytic processes. Additionally, the mesoporous nature promotes superior diffusion kinetics, facilitating better transport of reactants and products. This intricate interplay of structural elements contributes not only to the increased efficiency of electrochemical reactions but also to the extended durability of MPMNs during prolonged usage. This concept focus on the synthesis and design strategies of MPMNs, aligning with the dynamic requirements of diverse electrocatalytic applications. The synergy resulting from these advancements not only accentuates the intrinsic properties of MPMNs but also broadens their scope for practical implementation in emerging fields of electrochemistry.

High-entropy alloys in electrocatalysis: from fundamentals to applications

High-entropy alloys (HEAs) comprising five or more elements in near-equiatomic proportions have attracted ever increasing attention for their distinctive properties, such as exceptional strength, corrosion resistance, high hardness, and excellent ductility. The presence of multiple adjacent elements in HEAs provides unique opportunities for novel and adaptable active sites. By carefully selecting the element configuration and composition, these active sites can be optimized for specific purposes. Recently, HEAs have been shown to exhibit remarkable performance in electrocatalytic reactions. Further activity improvement of HEAs is necessary to determine their active sites, investigate the interactions between constituent elements, and understand the reaction mechanisms. Accordingly, a comprehensive review is imperative to capture the advancements in this burgeoning field. In this review, we provide a detailed account of the recent advances in synthetic methods, design principles, and characterization technologies for HEA-based electrocatalysts. Moreover, we discuss the diverse applications of HEAs in electrocatalytic energy conversion reactions, including the hydrogen evolution reaction, hydrogen oxidation reaction, oxygen reduction reaction, oxygen evolution reaction, carbon dioxide reduction reaction, nitrogen reduction reaction, and alcohol oxidation reaction. By comprehensively covering these topics, we aim to elucidate the intricacies of active sites, constituent element interactions, and reaction mechanisms associated with HEAs. Finally, we underscore the imminent challenges and emphasize the significance of both experimental and theoretical perspectives, as well as the potential applications of HEAs in catalysis. We anticipate that this review will encourage further exploration and development of HEAs in electrochemistry-related applications.

Electrocatalytic Activities of a Platinum Nanostructured Electrode Modified by Gold Adatom toward Methanol and Glycerol Electrooxidation in Acid and Alkaline Media

For practical applications such as fuel cells, it is important to exploit electrocatalysis with high activity for methanol and glycerol oxidation. A platinum nanostructured electrode (PtNPs) is modified by gold adatoms and is created by application of a square wave potential regime to a tantalum surface electrode. In nanostructured platinum, the structure and the surface properties are characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD) and cyclic voltammetry (CV). In acid and alkaline media, the CV and Chronoamperometric (CA) are studied to investigate the catalytic activity of the PtNPs nanoparticles for the electrooxidation of methanol and glycerol. The prepared nanostructured platinum on a tantalum electrode was allowed to balance an open circuit with a 1.0×10^-3 M solution containing an Au ion. Consequently, the proximity of the irreversibly adsorbed Au-adatoms on the already described Pt-nanostructured electrode. In acidic and alkaline solutions, the electrocatalytically activities toward methanol and glycerol oxidation were evaluated and is found to strongly on the surface of the gold-modified PtNPs. The PtNPs modified by Au electrode system used direct methanol fuel cell (DMFC) and direct glycerol fuel cell (DGFC). The DMFC and DGFC are much higher than in acid output in alkaline. Comparison of the i-E curves of nanostructure platinum electrode with that of a platinum nanostructure electrode modified by Au under similar conditions for the letter, the charge under the peak (i-E curve) in the oxidation region was higher. Furthermore, rough chronoamperometric measurements confirmed the results. The results of showed that the electrocatalytic properties of the nanostructured prepared surface were enhanced by the inclusion of gold adatoms with a variable extent of advancement. The current peak (I_p) and the current chronoamperometric (I_CA) of glycerol oxidation on the PtNPs electrode modified by Au in acid media (130 mA/cm², 47 µA/cm²) were higher than those of the bare PtNPs electrode and in alkaline media (171 mA/cm², 66 µA/cm²). The stronger catalytic behavior in alkaline media of the Au-PtNP electrode indicates its promising use in alkaline direct alcohol cells.

Nanotechnology‐based electrochemical biosensors for monitoring breast cancer biomarkers

Breast cancer is categorized as the most widespread cancer type among women globally. On-time diagnosis can decrease the mortality rate by making the right decision in the therapy procedure. These features lead to a reduction in medication time and socioeconomic burden. The current review article provides a comprehensive assessment for breast cancer diagnosis using nanomaterials and related technologies. Growing use of the nano/biotechnology domain in terms of electrochemical nanobiosensor designing was discussed in detail. In this regard, recent advances in nanomaterial applied for amplified biosensing methodologies were assessed for breast cancer diagnosis by focusing on the advantages and disadvantages of these approaches. We also monitored designing methods, advantages, and the necessity of suitable (nano) materials from a statistical standpoint. The main objective of this review is to classify the applicable biosensors based on breast cancer biomarkers. With numerous nano-sized platforms published for breast cancer diagnosis, this review tried to collect the most suitable methodologies for detecting biomarkers and certain breast cancer cell types.

PtCuRu Nanoflowers with Ru-Rich Edge for Efficient Fuel-Cell Electrocatalysis

Enhancing the catalytic activity of Pt-based alloy by a rational structural design is the key to addressing the sluggish kinetics of direct alcohol fuel cells. Herein, a facile one-pot method is reported to synthesize PtCuRu nanoflowers (NFs). The synergetic effect among Pt, Cu, and Ru can lower the d-band center of Pt, regulate the morphology, generate Ru-rich edge, and allow the exposure of more high index facets. The optimized Pt_0.68 Cu_0.18 Ru_0.14 NFs exhibit outstanding electrocatalytic performances and excellent anti-poisoning abilities. The specific activities for the methanol oxidation reaction (MOR) (7.65 mA cm^-2 ) and ethanol oxidation reaction (EOR) (7.90 mA cm^-2 ) are 6.0 and 7.1 times higher than commercial Pt/C, respectively. The CO stripping experiment and the chronoamperometric (5000 s) demonstrate the superior anti-poisoning property and durability performance. Density functional theory calculations confirm that high metallization degree leads to the decrease of d-band center, the promotion of oxidation of CO, and improvement of the inherent activity and anti-poisoning ability. A Ru-rich edge exposes abundant high index facets to accelerate the reaction kinetics of rate-determining steps by decreasing the energy barrier for forming *HCOOH (MOR) and CC bond breaking (EOR).

Ruthenium-based antitumor drugs and delivery systems from monotherapy to combination therapy

Ruthenium complex is an important compound group for antitumor drug research and development. NAMI-A, KP1019, TLD1433 and other ruthenium complexes have entered clinical research. In recent years, the research on ruthenium antitumor drugs has not been limited to single chemotherapy drugs; other applications of ruthenium complexes have emerged such as in combination therapy. During the development of ruthenium complexes, drug delivery forms of ruthenium antitumor drugs have also evolved from single-molecule drugs to nanodrug delivery systems. The review summarizes the following aspects: (1) ruthenium complexes from monotherapy to combination therapy, including the development of single-molecule compounds, carrier nanomedicine, and self-assembly of carrier-free nanomedicine; (2) ruthenium complexes in the process of ADME in terms of absorption, distribution, metabolism and excretion; (3) the applications of ruthenium complexes in combination therapy, including photodynamic therapy (PDT), photothermal therapy (PTT), photoactivated chemotherapy (PACT), immunotherapy, and their combined application; (4) the future prospects of ruthenium-based antitumor drugs.

Noble-Metal-Based Hollow Mesoporous Nanoparticles: Synthesis Strategies and Applications

As second-generation mesoporous materials, mesoporous noble metals (NMs) are of significant interest for their wide applications in catalysis, sensing, bioimaging, and biotherapy owing to their structural and metallic features. The introduction of interior hollow cavity into NM-based mesoporous nanoparticles (MNs), which subtly integrate hierarchical hollow and mesoporous structure into one nanoparticle, produces a new type of hollow MNs (HMNs). Benefiting from their higher active surface, better electron/mass transfer, optimum electronic structure, and nanoconfinement space, NM-based HMNs exhibit their high efficiency in enhancing catalytic activity and stability and tuning catalytic selectivity. In this review, recent progress in the design, synthesis, and catalytic applications of NM-based HMNs is summarized, including the findings of the groups. Five main strategies for synthesizing NM-based HMNs, namely silica-assisted surfactant-templated nucleation, surfactant-templated sequential nucleation, soft "dual"-template, Kirkendall effect in synergistic template, and galvanic-replacement-assisted surfactant template, are described in detail. In addition, the applications in ethanol oxidation electrocatalysis and hydrogenation reactions are discussed to highlight the high activity, enhanced stability, and optimal selectivity of NM-based HMNs in (electro)catalysis. Finally, the further outlook that may lead the directions of synthesis and applications of NM-based HMNs is prospected.

Synthesizing ordered mesoporous Ni spheres with uniform and adjustable size through a one-step Pd2+-assisted soft-templating strategy

Developing an effective way to synthesize uniform ordered mesoporous metal spheres with controllable diameter is important for enhancing their performance in various applications but remains a challenge. Herein, a one-step and facile Pd²⁺-assisted soft-templating strategy is reported to synthesize ordered mesoporous Ni spheres (OMNiS) with highly uniform and tunable diameters. In this synthesis methodology, lyotropic liquid crystals (LLCs) are used as a meso-structural template and Pd nuclei obtained from the reduction of Pd²⁺ ions are used as nucleation sites for directing Ni deposition. The OMNiS samples with average sphere diameter ranging from 50 nm to 190 nm are produced by varying the amount of Pd²⁺ in the LLC precursor, revealing that the Pd nuclei play a key role in improving the uniformity of the mesoporous Ni spheres and adjusting the sphere diameter. The satisfactory combination of uniform sphere size, high surface area, great conductivity, and highly ordered mesoporous structure for the optimal OMNiS-100 sample contributes to its superior electrocatalytic activity for the oxygen evolution reaction (OER) in an alkaline electrolyte with a low overpotential of 271 mV to drive a current density of 10 mA cm^-2, which is much smaller than that of RuO₂ (368 mV), along with a remarkable durability.

Monodisperse thiourea functionalized graphene oxide-based PtRu nanocatalysts for alcohol oxidation

Addressed herein, thiourea functionalized graphene oxide-based PtRu nanocatalysts (PtRu@T/GO) has been synthesized and characterized by several techniques and performed for methanol oxidation reactions as novel catalysts. In this study, graphene oxide (GO) was functionalized with thiourea (T/GO) in order to obtain monothiol functionalized graphene and increase the stability and activity of the nanocatalysts. Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), TEM (transmission electron microscopy) and high-resolution transmission electron microscopy (HR-TEM) were used for characterization of the prepared nanocatalysts. The results obtained from these techniques showed that the prepared nanocatalysts were in a highly crystalline form, well dispersed on T/GO, very small in size and colloidally stable. The average size of the synthesized nanocatalysts determined by TEM analysis was found to be 3.86 ± 0.59 nm. With HR-TEM analysis, the atomic lattice fringes of the nanocatalysts were calculated to be 0.23 nm. After the full characterization of the prepared nanocatalysts, they were tried for the methanol oxidation reaction (MOR) and it was observed that 97.3% of the initial performance was maintained even after 1000 cycles while exhibiting great catalytic activity and stability with the help of T/GO. Thus, the arranged nanocatalysts displayed great heterogeneous catalyst characteristics for the methanol oxidation response.

Monodisperse Pt-Co/GO anodes with varying Pt: Co ratios as highly active and stable electrocatalysts for methanol electrooxidation reaction

The intense demand for alternative energy has led to efforts to find highly efficient and stable electrocatalysts for the methanol oxidation reaction. For this purpose, herein, graphene oxide-based platinum-cobalt nanoparticles (Pt100-xCox@GO NPs) were synthesized in different ratios and the synthesized nanoparticles were used directly as an efficient electrocatalyst for methanol oxidation reaction (MOR). The characterizations for the determination of particle size and surface composition of nanoparticles were performed by transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The structure of the catalysts was detected as face-centered cubic and the dispersion of them on graphene oxide was homogenous (distributed narrowly (4.01 ± 0.51 nm)). Cyclic voltammetry (CV) and chronoamperometry (CA) was utilized for testing electrocatalytic activities of all prepared NPs for the methanol oxidation reaction. It was detected that the newly produced NPs were more active and stable than commercially existing Pt(0)/Co nanomaterial in methanol electro-oxidation in acidic media.

Mesoporous Pt@PtM (M = Co, Ni) cage-bell nanostructures toward methanol electro-oxidation

Rational design of Pt-based nanostructures with a controllable morphology and composition is vital for electrocatalysis. Herein, we demonstrate a dual-template strategy to fabricate well-defined cage-bell nanostructures including a Pt core and a mesoporous PtM (M = Co, Ni) bimetallic shell (Pt@mPtM (M = Co, Ni) CBs). Owing to their unique nanostructure and bimetallic properties, Pt@mPtM (M = Co, Ni) CBs show higher catalytic activity, better durability and stronger CO tolerance for the methanol oxidation reaction than commercial Pt/C. This work provides a general method for convenient preparation of cage-bell nanostructures with a mesoporous bimetallic shell, which have high promising potential for application in electrocatalytic fields.

An enhanced recyclable 3D adsorbent for diverse bio-applications using biocompatible magnetic nanomulberry and cucurbituril composites

Herein, we describe the synthesis of highly water-dispersible and biocompatible 3D adsorbents via a rapid two-step strategy employing a mesoporous magnetic nanomulberry-shaped Fe₃O₄ (MNM) on diatomaceous earth (DE) and cucurbituril (CB; MNM-DE-CB). Coating of CB on the surface of MNM-DE via hydrogen bonds not only enhanced the dispersibility of CB, but also improved the stability of MNM-DE. The ability of the adsorbent to remove dyes from water was investigated as a function of metal ions, solution pH, temperature, and concentration to determine optimum reaction conditions. Unlike MNM-DE, MNM-DE-CB exhibited highly efficient, rapid dye removal and recyclability in aqueous solution, and low cytotoxicity toward cancer cells in drug delivery tests. MNM-DE-CB is a promising green adsorbent with potential for diverse applications including water remediation, interface catalysis, bio-sample preparation, and drug delivery.

Integration mesoporous surface and hollow cavity into PtPdRh nano-octahedra for enhanced oxygen reduction electrocatalysis

Design and synthesis of Pt-based nanocrystals with controlled structural diversity and complexity can potentially bring about multifunctional properties. In this work, we present a facile two-step strategy for the construction of the PtPdRh mesoporous octahedral nanocages (PtPdRh MONCs). This unique nanoarchitectonics rationally integrates multiple advantages (i.e. the octahedral shape, hollow cavity and mesoporous surface) into one catalyst, which facilitates the efficient utilization of noble metal atoms at both of the interior and exterior surfaces. As expected, the resultant PtPdRh MONCs could effectively catalyze the oxygen reduction reaction (ORR) under acidic conditions. The demonstrated ORR activity and catalytic durability are superior to the commercial Pt/C catalyst. The present study would provide a general guidance for architectural and compositional engineering of noble metal nanocrystals with desired functionalities and properties.

Plasmonic mesoporous AuAg nanospheres with controllable nanostructures

Three kinds of plasmonic mesoporous AuAg (mesoAuAg) nanospheres, including well-alloyed mesoAuAg, hollow mesoAuAg, and core-shell Ag-mesoAu nanospheres, were successfully synthesized by carefully controlling the reduction kinetics of metal precursors in the presence of a functional surfactant, C22H45N+(CH3)2-C3H6-SH(Cl-). The resulting mesoAuAg exhibited a remarkable structure-dependent electrocatalytic performance toward methanol oxidation reaction.

Low Dimensional Platinum-Based Bimetallic Nanostructures for Advanced Catalysis

The development of renewable energy storage and conversion has been greatly promoted by the achievements in platinum (Pt)-based catalysts, which possess remarkable catalytic performance. However, the high cost and limited resources of Pt have hindered the practical applications and thus stimulated extensive efforts to achieve maximized catalytic performance with minimized Pt content. Low dimensional Pt-based bimetallic nanomaterials (such as nanoplates and nanowires) hold enormous potential to realize this target owing to their special atomic arrangement and electronic structures. Recent achievements reveal that strain engineering (e.g., the compressive or tensile strain existing on the Pt skin), surface engineering (e.g., high-index facets, Pt-rich surface, and highly open structures), and interface engineering (e.g., composition-segregated nanostructures) for such nanomaterials can readily lead to electronic modification, more active sites, and strong synergistic effect, thus opening up new avenues toward greatly enhanced catalytic performance. In this Account, we focus on recent advances in low dimensional Pt-based bimetallic nanomaterials as promising catalysts with high activity, long-term stability, and enhanced selectivity for both electrocatalysis and heterogeneous reactions. We begin by illustrating the important role of several strategies on optimizing the catalytic performance: (1) regulated electronic structure by strain effect, (2) increased active sites by surface modification, and (3) the optimized synergistic effect by interfacial engineering. First of all, a difference in atomic bonding strength can result in compressive or tensile force, leading to downshift or upshift of the d-band center. Such effects can be significantly amplified in low-dimensionally confined nanostructures, producing optimized bonding strength for improved catalysis. Furthermore, a high density of high-index facets and a Pt-rich surface in shape-controlled nanostructures based on surface engineering provide further enhancement due to the increased Pt atom utilization and optimal adsorption energy. Finally, interfacial engineering of low dimensional Pt-based bimetallic nanomaterials with high composition-segregation can facilitate the catalytic process due to a strong synergetic effect, which effectively tunes the electronic structure, modifies the coordination environment, and prevents catalysts from serious aggregation. The rational design of low dimensional Pt-based bimetallic nanomaterials with superior catalytic properties based on strain, surface, and interface engineering could help realize enhanced catalysis, gain deep understanding of the structure-performance relationship, and expand access to Pt-based materials for general communities of materials science, chemical engineering, and catalysis in renewable energy research fields.

Highly monodisperse Pd-Ni nanoparticles supported on rGO as a rapid, sensitive, reusable and selective enzyme-free glucose sensor

In this work, highly monodispersed palladium-nickel (Pd-Ni) nanoparticles supported on reduced graphene oxide (rGO) were synthesized by the microwave-assisted methodology. The synthesized nanoparticles were used for modification of a glassy carbon electrode (GCE) to produce our final product as PdNi@rGO/GCE, which were utilized for non-enzymatic detecting of glucose. In the present study, electrochemical impedance spectroscopy (EIS), chronoamperometry (CA) and, cyclic voltammetry (CV) methods were implemented to investigate the sensing performance of the developed glucose electrode. The modified electrode, PdNi@rGO/GCE, exhibited very noticeable results with a linear working range of 0.05-1.1 mM. Moreover, an ultralow detection limit of 0.15 μM was achieved. According to the results of amperometric signals of the electrodes, no significant change was observed, even after 250 h of operation period. In addition, the highly monodisperse PdNi@rGO/GCE was utilized to electrochemical detection of glucose in real serum samples. In light of the results, PdNi@rGO/GCE has shown an excellent sensing performance and can be used successfully in serum samples for glucose detection and it is suitable for practical and clinical applications.

Synthesis and characterization of Rosa canina-mediated biogenic silver nanoparticles for anti-oxidant, antibacterial, antifungal, and DNA cleavage activities

In biomedical applications, silver nanoparticles (Ag NPs) are of great interest due to their cost-effective and environmentally friendly properties. Green synthesis of nanoparticles for biological research is a preferred choice since it does not require additional reducing agent. For this purpose, in this study, we aimed to synthesize the biogenic silver nanoparticles with the help of Rosa canina plant (Rc-Ag NPs) and then they have been tried for their antioxidant and antibacterial properties. UV-Vis spectrophotometer, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analyses were performed for characterization of Rc-Ag NPs. Antioxidant properties of silver nanoparticles synthesized with Rosa canina plant were investigated against 2,2′-diphenyl-1-picrylhydrazyl radical (DPPH). DNA dissociation activity of synthesized Rc-Ag NPs was studied, and DNA dissociation activity was shown. The antimicrobial activity of Rc-Ag NPs was also tested using micro-dilution. According to the results, Rc-Ag NPs synthesized were found to be highly effective for anti-oxidant, antibacterial, antifungal, and DNA cleavage activities.

Engineering the Structure of Mesoporous Bioactive Glass Microspheres by the Surface Effect of Inverse Opal Templates and Temperature

The interactions of ions and molecules with material surface are highly dependent on the surface properties of the material. Therefore, the distribution of ions or molecules near the material surface may be affected by the surface properties. This phenomenon can be significant enough for controlling the structure of a material synthesized in the sub-micrometer scale confinement space of a template. This work confirms that inverse opals are perfect templates for offering confinement space, while their different surface properties can strongly affect ion and block copolymer distribution in the confinement space. This surface effect principle can be used for the controlled synthesis of colloids with complex composition. As an example, four kinds of mesoporous magnetic bioactive glass colloids with ordered mesopores, core-shell structure, open surface pores, or disordered mesopores are prepared by using polystyrene and carbon inverse opal templates. This work reveals that inverse opal templates possess great advantage in controlled synthesizing colloidal structures due to their surface effect on ions and molecules and confinement space.

Interface engineering of Ni5P2 nanoparticles and a mesoporous PtRu film heterostructure on Ni foam for enhanced hydrogen evolution

Engineering of multicomponent heterostructures can yield exceptional functionalities and enhance electrocatalytic activities by a synergistic effect. Herein, Ni₅P₂ nanoparticle-decorated mesoporous PtRu film on Ni foam (Ni₅P₂-mPtRu/NF) has been synthesized via a facile two-step strategy. Ni₅P₂-mPtRu/NF possesses a well-developed continuous mesoporous structure and strong electronic interaction between Ni₅P₂ and PtRu, exhibiting an enhanced electrocatalytic performance towards an alkaline hydrogen evolution reaction (HER). Ni₅P₂-mPtRu/NF achieves a current density of 10 mA cm^-2 at an overpotential of 28.8 mV and a low Tafel slope of 56.5 mV dec^-1, and has excellent durability. This work provides a promising pathway for developing self-supported mesoporous multicomponent heterostructures as efficient electrocatalysts for an alkaline HER.

A POSS-Phosphazene Based Porous Material for Adsorption of Metal Ions from Water

The development of adsorptive materials continues to be an important area of research for removal of heavy metal ions from waste water. The adsorption capacity can be modulated by both physical and chemical modification of the adsorbent. Herein, we combine the unique properties of polyhedral oligomeric silsesquioxane (POSS) and organocyclophosphazene as the building units to synthesize a hybrid porous material, abbreviated as PN-POSS. The synthetic method follows a Heck reaction between hexa(4-bromophenoxy)cyclotriphosphazene and octavinylsilsesquioxane (OVS). The Brunauer-Emmett-Teller (BET) analysis shows that the material possesses micro- and mesopores of 1.5 and 3.8 nm size and a surface area on the order of 500 m²  g^-1 . These attributes in combination with the donor ability of the phosphazene units qualify the material for high adsorption of Pb²⁺ , Hg²⁺ and Cu²⁺ ions with maximal adsorption capacities on the order of 1326, 1927 and 2654 mg g^-1 , respectively. The adsorbent exhibits a good regeneration performance and can be effectively used for water treatment.

Synthesis and characterization of Reishi mushroom-mediated green synthesis of silver nanoparticles for the biochemical applications

In recent years, the synthesis of nanoparticles via biological processes has attracted considerable attention. The use of plants and plant extracts is one of the most preferred methods for biological synthesis due to their rich biologically active metabolites. In this study, silver nanoparticles (Ag NPs) were synthesized using reishi mushroom (Ganoderma lucidum) extract. Different analytical techniques including X-ray Photoelectron Spectroscopy (XPS), X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-vis spectroscopy, and Fourier Transform Infrared Spectrophotometer (FTIR) were used for the characterization of Ag NPs. UV-vis spectrum exhibited a broad absorption peak between 400-460 nm which indicates the existence of Ag NPs. TEM images showed Ag NPs are spherical with a diameter range of 15-22 nm. In addition, it is shown that Ag NPs form a face-centered cubic structure according to XRD characterization technique. The antioxidant activity towards to 1-Diphenyl-2-picrylhydrazyl (DPPH) was also studied. The highest DPPH scavenging percentage was recorded as 76.45% at 250 mg/L. The DNA cleavage activity results indicated that the green Ag NPs caused single strain DNA cleavage activity for 30 and 60 min at 50 and 100 mg/L, respectively. The Ag NPs antimicrobial activity was also investigated and results recorded as minimum inhibition concentration (MIC). Ag NPs showed a strong antibacterial effect against gram-positive (S. aureus, E. hirae, B. cereus) and gram-negative (E. coli, P. aeruginosa, L. pneumophila subsp. Pneumophila) bacteria. Furthermore, Ag NPs have also been shown to have a high antifungal effect against C. albicans fungus.

Facile Synthesis of GNPs@NixSy@MoS2 Composites with Hierarchical Structures for Microwave Absorption

Graphene-based powder absorbers have been used to attain excellent microwave absorption. However, it is not clear if inferior microwave absorption by pure graphene materials can be attributed to impedance mismatching or inadequate attenuation capability. In this comparative study, we focus on these aspects. Graphene nanoplatelets (GNPs) multi-component composites (GNPs@Ni_xS_y@MoS₂) were prepared by hydrothermal reaction with different S and Mo molar ratios. The morphologies, phase crystals, elemental composition, and magnetic properties of the composites were also analyzed. In addition, microwave absorption of the as-prepared samples was investigated and it revealed that the impedance mismatching could be responsible for inferior microwave absorption; higher conductivity can lead to skin effect that inhibits the further incidence of microwaves into the absorbers. Furthermore, the optimum reflection loss (RL) of GNPs@Ni_xS_y@MoS₂-2 can reach -43.3 dB at a thickness of 2.2 mm and the corresponding bandwidth with effective attenuation (RL < -10 dB) of up to 3.6 GHz (from 7.0 to 10.6 GHz). Compared with the GNPs, the enhanced microwave absorption can be assigned to the synergistic effects of conductive and dielectric losses.

Insights into Compositional and Structural Effects of Bimetallic Hollow Mesoporous Nanospheres toward Ethanol Oxidation Electrocatalysis

A one-pot soft-templating method is reported to fabricate nanosized bimetallic PdAg hollow mesoporous nanospheres (HMSs) for electrocatalytic ethanol oxidation reaction (EOR). The synthesis relies on the "dual-template" surfactant of dioctadecyldimethylammonium chloride that drives in situ growth of mesoporous frameworks on the surface of vesicles into the HMSs with radially opened mesochannels. The synthetic protocol is extendable to engineer elemental compositions and hierarchical nanostructures of PdAg nanoalloys. This system thus provides a direct yet solid platform to understand catalytic add-in synergies of PdAg HMSs toward electrochemical EOR. By evaluating compositional and structural features separately, bimetallic Pd₆₅Ag₃₅ HMSs display the highest EOR activity with a mass activity of 4.61 A mg_Pd^-1. Mechanism studies indicate that synergistically electronic and bifunctional effects as well as structural advantages of Pd₆₅Ag₃₅ HMSs kinetically optimize the removal of poisoning carbonaceous intermediates and accelerate the diffusion processes (the rate-determining step), and thus promote the EOR performance accordingly.

Morphology-Tailored Gold Nanoraspberries Based on Seed-Mediated Space-Confined Self-Assembly

Raspberry-like structure, providing a high degree of symmetry and strong interparticle coupling, has received extensive attention from the community of functional material synthesis. Such structure constructed in the nanoscale using gold nanoparticles has broad applicability due to its tunable collective plasmon resonances, while the synthetic process with precise control of the morphology is critical in realizing its target functions. Here, we demonstrate a synthetic strategy of seed-mediated space-confined self-assembly using the virus-like silica (V-SiO₂) nanoparticles as the templates, which can yield gold nanoraspberries (AuNRbs) with uniform size and controllable morphology. The spikes on V-SiO₂ templates serve dual functions of providing more growth sites for gold nanoseeds and activating the space-confined effect for gold nanoparticles. AuNRbs with wide-range tunability of plasmon resonances from the visible to near infrared (NIR) region have been successfully synthesized, and how their geometric configurations affect their optical properties is thoroughly discussed. The close-packed AuNRbs have also demonstrated huge potential in Raman sensing due to their abundant “built-in” hotspots. This strategy offers a new route towards synthesizing high-quality AuNRbs with the capability of engineering the morphology to achieve target functions, which is highly desirable for a large number of applications.

Fine Control over the Compositional Structure of Trimetallic Core-Shell Nanocrystals for Enhanced Electrocatalysis

Pt-based multimetallic nanocrystals (NCs) have attracted tremendous research interest because of their excellent catalytic properties in various electrocatalysis fields. However, the development of rational synthesis approaches that can give multimetallic NCs with desirable compositional structures is still a radical issue. In the present work, we devised an efficient strategy for the systematic control of the spatial distribution of constituent elements in Pt-based trimetallic core-shell NCs, through which NCs with distinctly different compositional structures, such as Au@PdPt, Au@Pd@Pt, AuPd@Pt, and AuPdPt@Pt core-shell NCs, could selectively be generated. The adjustment of the amount of a reducing agent, hydrazine, which can provide control over the relative reduction kinetics of multiple metals, is the key to the selective formation of NCs. Through extensive studies on the effect of the compositional structure of the trimetallic NCs on their catalytic function toward the methanol electro-oxidation reaction, we found that the Au@Pd@Pt NCs exhibited considerably enhanced catalytic performance in comparison to the other trimetallic NCs as well as to their binary counterparts, a commercial catalyst, and reported Pt-based nanocatalysts due to the optimized surface electronic structure. The present strategy will be useful to design and construct multicomponent catalytic systems for various energy and environmental applications.

Tuning Cooperative Assembly with Bottlebrush Block Co-polymers for Porous Metal Oxide Films Using Solvent Mixtures

Block copolymer templating enables the generation of well-defined pore sizes and geometries in a wide variety of frameworks, typically through evaporation-induced self-assembly (EISA). Here, we systematically modulate the solvent quality with mixtures of tetrahydrofuran-ethanol (THF-EtOH) to manipulate the unimer/micelle ratio in the precursor solution to explore how the associated solution structure influences the final pore morphology. A bottlebrush block copolymer (BBCP) with poly(ethylene oxide) and poly(t-butyl acrylate) side chains was used as the template for pore formation. Irrespective of the solvent composition, a bimodal pore size distribution was obtained with mesopores templated by small aggregates of the BBCP unimers (potentially low aggregation number micelles) and macropores templated by large self-assembled BBCP micelles. The morphology and pore characteristics of the metal oxide films were dependent on the THF-EtOH composition. Interestingly, an intermediate solvent composition where the volume of micelles is approximately half the volume of unimers (in the precursor solution) leads to the best ordering of micelle-templated pores and also the maximum porosity in the films. The micelle/unimer ratios in the precursor solutions do not correspond directly to the bimodal pore distribution in the metal oxide films, which we attribute to kinetically trapped assembly of the BBCP at a low THF content. The increased critical micelle concentration at high THF composition leads to changes in the unimer/micelle ratio during solvent evaporation. These results appear to be universal for a number of metal oxides (cobalt, magnesium, and zinc) with the porosity maximized at a THF/EtOH ratio of 3:1. These results suggest the potential for enhancements in the porosity of block copolymer-templated films by EISA methods through judicious solvent selection.

Catalyst-Free One-Step Preparation of Self-Crosslinked pH-Responsive Vesicles

The fabrication of block copolymer (BCP) vesicles with controlled membrane permeability and promising stability remains a considerable challenge. Herein, a new type of pH-responsive and self-crosslinked vesicle based on a hydrolytically hindered urea bond is reported. This kind of vesicle is formed by the self-assembly of a pH-responsive and hydrolytically self-crosslinkable copolymer poly(ethylene glycol)-block-poly[2-(3-(tert-butyl)-3-ethylureido)ethyl methacrylate-co-2-(diethylamino)ethyl methacrylate] (PEG-b-P(TBEU-co-DEA)). The BCP can be easily synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization of 2-(3-(tert-butyl)-3-ethylureido)ethyl methacrylate (TBEU) and 2-(diethylamino)ethyl methacrylate (DEA) using PEG-based macro-chain transfer agent. The copolymer could self-assemble into stable vesicles by the hydrophobic interaction and in situ cross-linking between amines and isocyanates after the hydrolysis of the hindered urea bonds without any catalyst. Dynamic light scattering (DLS) studies show that the vesicles exhibit enhanced stability against the dilution of organic solvent, and the size can be adjusted through the change of pH values. Moreover, the alkaline phosphatase-loaded vesicles can act as nano-reactor and enable free diffusion of small molecules into the vesicles, followed by the significantly improved fluorescence intensity of phosphate-caged fluorescein. This self-crosslinking and pH-sensitive vesicles may serve as a smart platform in controlled drug delivery and molecular reactor.

Hollow mesoporous ruthenium nanoparticles conjugated bispecific antibody for targeted anti-colorectal cancer response of combination therapy

Combined treatment based on tumor-targeted nanoparticles has become one of the most promising anticancer strategies. Moreover, bispecific antibodies have been designed as linkers to promote the interaction between natural killer (NK) cells and tumor cells, while triggering NK cell-mediated target cell lysis. Here, we adopted a novel design that uses PEGylated hollow mesoporous ruthenium nanoparticles as a carrier to load the fluorescent anti-tumor complex ([Ru(bpy)2(tip)]2+, RBT) and a conjugate with bispecific antibodies (SS-Fc). By accurately targeting carcinoembryonic antigen overexpressed in colorectal cancer cells, HMRu@RBT-SS-Fc significantly improved selective penetration in vitro. The functionalized nanocomplex effectively engaged NK cells and possessed excellent near infrared-sensitive cytotoxicity. Systematic in vivo studies clearly demonstrated the high tumor targeting and anticancer activity in heterotopic colorectal tumor model via combined photothermal and immune therapy. This nanosystem establishes a new platform for future image-guided drug delivery and highly efficient cancer therapy.

Trimetallic PtPdCo mesoporous nanopolyhedra with hollow cavities

The rational design of metallic mesoporous nanoarchitectures with hollow cavities offers an effective way to boost their performance in various catalytic fields. Herein, we report a facile two-step strategy for the fabrication of trimetallic PtPdCo mesoporous nanopolyhedra with hollow cavities (PtPdCo MHNPs), in which Pd@PtPdCo core-shell mesoporous nanopolyhedra (Pd@PtPdCo MNPs) are directly prepared by a simple chemical reduction reaction followed by etching of the Pd cores. The PtPdCo MHNPs show enhanced electrocatalytic activity and durability for the methanol oxidation reaction, enabled by their mesoporous and hollow nanoarchitectures coupled with trimetallic compositions.

PtPdRh Mesoporous Nanospheres: An Efficient Catalyst for Methanol Electro-Oxidation

Porous multimetallic alloyed nanostructures possess unique physical and chemical properties to generate promising potential in fuel cells. However, the controllable synthesis of this kind of materials still remains challenging. Herein, we report a facile method for the one-pot, high-yield synthesis of trimetallic PtPdRh mesoporous nanospheres (PtPdRh MNs) under mild conditions. The resultant PtPdRh MNs possess the features of uniform shape, a narrow size distribution, plenty of well-defined mesopores, highly open structure, and multicomponent effects, which impart advantages such as large surface area, favorable mass diffusion, high utilization of electrocatalysts, and synergy among the various metal components. Benefitting from the synergetic effects originating from the multimetallic composition and unique mesoporous structure, the as-prepared PtPdRh MNs exhibit remarkably enhanced electrocatalytic performance for methanol oxidation reaction relative to bimetallic PtPd MNs and commercial Pt/C catalyst.

The rational synthesis of aerosol-assisted alumina powders having uniform mesopores and highly accessible surfaces

Several important factors to fabricate high-quality aerosol-assisted mesoporous alumina powders are summarized by considering rational and reliable synthetic routes.

Solvent-free and rapid synthesis of mesoporous Pt–iron oxide catalysts via mechanochemical assembly

Mechanochemical assembly enables the solvent-free construction of plentiful mesopores and highly dispersed Pt NPs in iron oxide catalysts.

Transferrin/aptamer conjugated mesoporous ruthenium nanosystem for redox-controlled and targeted chemo-photodynamic therapy of glioma

The blood-brain barrier (BBB) and low targeting are major obstacles for the treatment of gliomas. Accordingly, overcoming the BBB and enhancing the targeting of drugs to the glioma area are key to achieving a good therapeutic effect. Here, we have developed the mesoporous ruthenium nanosystem RBT@MRN-SS-Tf/Apt with dual targeting function. Transferrin (Tf) and aptamer AS1411 (Apt) are grafted on the surfaces of mesoporous ruthenium nanoparticles (MRN) with high loading capacity. This is achieved via redox-cleavable disulfide bonds, serving as both a capping agent and a targeting ligand, enabling the effective penetration of the blood-brain barrier and targeting the glioma. In addition, RBT@MRN-SS-Tf/Apt can specifically kill glioma cells in vitro and in vivo. Moreover, anti-tumor drugs [Ru(bpy)₂(tip)]²⁺ (RBT) will produce reactive oxygen species and induce apoptosis of tumor cells under laser irradiation, providing photodynamic therapy (PDT) for the treatment of gliomas, and further prolonging the median survival period. The study shows that this chemical photodynamic therapy nanosystem can be used as an efficient and powerful synergistic system for the treatment of brain tumors and other brain diseases of the central nervous system. STATEMENT OF SIGNIFICANCE: In order to overcome the blood-brain barrier and low targeting, and enhance the anti-glioma activities of nanodrugs. We have developed RBT@MRN-SS-Tf/Apt with dual targeting function. It is achieved release drug via redox-cleavable disulfide bonds, and enable the effective penetration of the blood-brain barrier and targeting the glioma. Moreover, anti-tumor drugs RBT will produce reactive oxygen species and induce apoptosis of tumor cells under laser irradiation, providing photodynamic therapy (PDT) for the treatment of gliomas, and further prolonging the median survival period. Therefore, this chemical photodynamic therapy nanosystem can be used as an efficient and powerful synergistic system for the treatment of brain tumors and other brain diseases of the central nervous system.

Multimetallic Hollow Mesoporous Nanospheres with Synergistically Structural and Compositional Effects for Highly Efficient Ethanol Electrooxidation

Controlling the nanostructures and chemical compositions of the electrochemical nanocatalysts has been recognized as two prominent means to kinetically promote the electrocatalytic performance. Herein, we report a general "dual"-template synthesis methodology for the formation of multimetallic hollow mesoporous nanospheres (HMSs) with an adjustable interior hollow cavity and cylindrically opened mesoporous shell as a highly efficient electrocatalyst for ethanol oxidation reaction. Three-dimensional trimetallic PdAgCu HMSs were synthesized via in situ coreduction of Pd, Ag, and Cu precursors on "dual"-template structural directing surfactant of dioctadecyldimethylammonium chloride in optimal synthesis conditions. Due to synergistic advantages on hollow mesoporous nanostructures and multimetallic compositions, the resultant PdAgCu HMSs exhibited significantly enhanced electrocatalytic performance toward ethanol oxidation reaction with a mass activity of 5.13 A mg_Pd ^-1 at a scan rate of 50 mV s^-1 and operation stability (retained 1.09 A mg_pd ^-1 after the electrocatalysis). The "dual"-template route will open a new avenue to rationally design multimetallic HMSs with controlled functions for broad applications.

Synthesis of Co–Mn oxides with double-shelled nanocages for low-temperature toluene combustion

In this paper, we report a template-engaged strategy for the synthesis of Co–Mn oxides with double-shell box-in-box hollow nanocage (BHNC) structures.

Rational one-step synthesis of porous PtPdRu nanodendrites for ethanol oxidation reaction with a superior tolerance for CO-poisoning

Precise fabrication of porous ternary Pt-based nanodendrites is very important for electrochemical energy conversion owing to high surface area and great molecular accessibility of these nanodendrites. Herein, PtPdRu porous nanodendrites (PNDs) were prepared via a facile one-step ultrasonic irradiation approach at room temperature. Intriguingly, the ultrasonic irradiation drove the formation of PtPdRu PNDs with spatially interconnected porous structures, whereas magnetic stirring produced PtPdRu nanoflowers (NFs) with less porosity. The formation mechanism was ascribed to the acoustic cavitation effect and fast-reduction kinetics under sonication. The as-made PtPdRu PNDs displayed a superior catalytic performance towards ethanol oxidation reaction with a high tolerance for CO-poisoning as compared to PtPdRu NFs, PtPd NDs, and commercial Pt/C catalyst.