Luminescence intensification of lanthanide complexes by silver nanoparticles incorporated in sol-gel matrix

We present how the luminescence of europium RR-2-P-oxides complexes can be increased by interaction of electronic levels of the complex with the radiation field of silver nanoparticles （NPs）. The procedure by which silver NPs are formed in a sol-gel polyurethane matrix precursor was elaborated. The formed Ag NPs were combined with Eu complex incorporated in ormocer matrix. The emission spectra of the complexes without silver NPs were compared with spectra of the same complexes with addition of silver NPs. As the result of the interaction of the electronic levels of lanthaaide ligands with silver plasmons, dramatic increase of luminescence was observed.

Preparation and Characterization of Carboxyl Functionalized Fluorescent Mesoporous Silica Nanoparticles Containing 8-Hydroxyquinolinate Zinc Complexes

Fluorescent mesoporous silica nanoparticles functionalized with carboxyl group(Znq-CMSCOOH) were successfully synthesized by in situ formation route of 8-hydroxyquinolinate zinc complexes in channels of mesoporous silica nanoparticles and post-grafting of carboxyl group on the surface. Moreover,the particle size and structural properties of Znq-CMS-COOH were characterized by transmission electron microscopy(TEM),field emission scanning electron microscopy(FE-SEM),dynamic light scattering(DLS),Fourier transform infrared spectroscopy(FT-IR),UV-vis spectrometer, fluorescence spectrometer and nitrogen adsorption-desorption measurements. The obtained results suggest that the Znq-CMS-COOH presents the uniform spherical shape with the mean diameter of about 85 nm and the obvious wormhole arrangement mesoporous. In addition, the Znq-CMS-COOH possesses green fluorescence with the emission peaks at 495 nm. So the Znq-CMS-COOH, which is beneficial to further modification and tracing, might be a great potential carrier for applying in drug delivery system in the future.

Metal–Oleate Complex?Derived Bimetallic Oxides Nanoparticles Encapsulated in 3D Graphene Networks as Anodes for Efficient Lithium Storage with Pseudocapacitance

In this manuscript, we have demonstrated the delicate design and synthesis of bimetallic oxides nanoparticles derived from metal–oleate complex embedded in 3D graphene networks(MnO/CoMn_2O_4  GN), as an anode material for lithium ion batteries. The novel synthesis of the MnO/CoMn_2O_4  GN consists of thermal decomposition of metal–oleate complex containing cobalt and manganese metals and oleate ligand, forming bimetallic oxides nanoparticles, followed by a selfassembly route with reduced graphene oxides. The MnO/CoMn_2O_4  GN composite, with a unique architecture of bimetallic oxides nanoparticles encapsulated in 3D graphene networks, rationally integrates several benefits including shortening the di usion path of Li^+ ions, improving electrical conductivity and mitigating volume variation during cycling. Studies show that the electrochemical reaction processes of MnO/Co Mn_2O_4  GN electrodes are dominated by the pseudocapacitive behavior, leading to fast Li^+ charge/discharge reactions. As a result, the MnO/CoMn_2O_4  GN manifests high initial specific capacity, stable cycling performance, and excellent rate capability.

Facile synthesis of La_2Mo_2O_9 nanoparticles via an EDTA complexing approach

A facile EDTA （ethylene diamine tetraacetic acid） complexing technique has been successfully employed to prepare La2Mo2O9 nanoparticles. The as-synthesized products are characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, and Fourier transform infrared spectroscopy （FT-IR）. The results show that a homogeneous transparent gel can be obtained with EDTA as the organic complexing reagent under the pH value of 3.0. Further thermal decomposition of the as-synthesized transparent gel by increasing the temperature up to 600℃ for 3 h results in the formation of La2Mo2O9 nanoparticles with a crystal size of about 30 nm. Moreover, the nanoparticles tend to form micrometer-sized aggregates with a three-dimensional network structure, which shows promising applications in solid oxide fuel cells （SOFC）, catalysts and so on.

Synthesis of Chiral Schiff Base Metal Complex Inducing CD and Elucidation of Structure of Adsorption on Surface of Gold Nanoparticles

We have prepared supramolecular systems of chiral Schiff base Ni(II), Cu(II), Zn(II) complexes and colloidal gold nanoparticles (AuNP) of 10 nm diameters. They demonstrated that direct adsorption of chiral Schiff base metal complex on the surface of AuNP owing to observation of clear induced CD spectra for the first time. We observed and discussed induced CD bands on AuNP from chiral Schiff base Ni(II), Cu(II), Zn(II) complexes.

Rapid Synthesis of Size-controlled Gold Nanoparticles by Complex Intramolecular Photoreduction

A rapid synthesis of size-controlled gold nanoparticles was proposed.The method is based on the sensitive intramolecular photoreduction reaction of Fe（Ⅲ）-EDTA complex in chloroacetic acid-sodium acetate buffer solution,where Fe（Ⅱ）-EDTA complex generated by photo-promotion acts as a reductant of AuCl-4 ions.Gold nanoparticles formed were stabilized by EDTA ligand or other protective agents added.As a result,well-dispersed gold nanoparticles with an average diameter range of 6.7 to 50.9 nm were obtained.According to the characterizations by the UV spectrum and TEM,the intramolecular charge transfer of the excited states of complex Fe（Ⅲ）-EDTA and the mechanism of forming gold nanoparticles were discussed in detail.

Optical Properties of Chiral Azo-Schiff Base Mn(II) and Zn(II) Complexes with Silver Nanoparticles

Herein we have originally designed chiral azo-salen Mn(II) and Zn(II) complexes for interacting silver nanoparticles (AgNPs) exhibiting localized surface plasmon resonance (LSPR). Understanding excited state and reaction intermediate during light irradiation to return to ground state may be important for such composite systems. Therefore, we investigated such optical properties for systems using time-resolved luminescence and transient absorption measurements. DMSO solutions of the four newly prepared and characterized complexes (MMn, MZn, CMn, and CZn) and ethanol solutions of the composite materials of each complex with AgNPs were served for optical measurements. The time-correlated single photon counting (TCSPC), the streak camera which is much shorter period of time than TCSPC and transient absorption measurement, was performed for the eight samples. The fluorescence lifetime of the sole complexes and the composite materials with AgNPs was derived from curve-fitting analysis of luminescence decay curves of TCSPC. Lifetime of the composite systems with AgNPs was longer than that of the corresponding sole metal complexes for three cases. It was revealed that composite systems may go through three reaction intermediates during relaxation from excited state to ground state.

Adsorption behavior and adsorption mechanism of Cu(Ⅱ) ions on amino-functionalized magnetic nanoparticles

Amino-functionalized magnetic nanoparticle （NH2-MNP） were prepared by a sol-gel approach. The adsorption behavior of Cu（II） ions on NH2-MNP was discussed systematically by batch experiments. The effects of initial Cu（II） ions concentration, time, pH and temperature were investigated. In kinetic studies, the pseudo-second-order model was successfully employed, and the pseudo-first-order model substantiated that Cu（II） adsorption on NH2-MNP was a diffusion-based process. Langmuir model and Dubinin-Radushkevich model （R2〉0.99） were more corresponded with the adsorption isotherm data of Cu（II） ions than Freundlich model. The adsorption capacity was increased with the increment of temperature and pH. NH2-MNP remains excellent Cu（II） recoveries after reusing five adsorption and desorption cycles, making NH2-MNP a promising candidate for repetitively removing heavy metal ions from environmental water samples. According to the results obtained from adsorption activation energy and thermodynamic studies, it can be inferred that the main adsorption mechanism between absorbent and Cu（II） ions is ion exchange-surface complexation.

Green synthesis and characterization of palladium nanoparticles and its conjugates from solanum trilobatum leaf extract

An important area of research in nanotechnology deals with the synthesis of nanoparticles of different chemical compositions,sizes and controlled monodispersity.Currently,there is a growing need to develop environmentally benign nanoparticle synthesis in which no toxic chemicals are used in the synthesis protocol.Palladium nanoparticles(Pd Np) are of interest because of their catalytic properties and affinity for hydrogen.Our protocol for the phyto-synthesis of Pd Np under moderate p H and room temperature offers a new means to develop environmentally benign nanoparticles.Solanum trilobatum is enlightened in our present study as it is enriched with phytochemicals to reduce palladium chloride ions.Poly MVA a dietary supplement based on the nontoxic chemotherapeutic lipoic acid-palladium complex(LA-Pd) is been hypothesized as the new paradigm of cancer therapy.Hence forth we successfully conjugated lipoic acid(S-Pd Np-LA) and vitamins(S-Pd Np-Vitamin-LA) to palladium nanoparticles synthesised from Solanum trilobatum leaf extract.These nanoparticles(S-Pd Np,S-Pd Np-LA,S-Pd Np-Vitamin-LA) were characterized with UV-Vis Spectroscopy,SEM and FTIR analysis,which revealed that S-Pd Np are polydisperse and of different morphologies ranging from 60?70 nm(S-Pd Np),65?80 nm(S-Pd Np-LA) and 75?100 nm(S-Pd Np-Vitamin-LA) in size.

Fluorescence Enhancement of a Polymer Planar Waveguide Doped with Rhodamine B and Ag Nanoparticles

Planar polymer multi-model waveguides doped with Ag nano-particles and rhodamine B are fabricated and investigated by the spectroscopy analysis method as well as the M-line method. Experimental results shown that fluorescence enhancement occurs when excited by a wide band wavelength with Ag nano-particle concentration at a certain level. The maximum enhancement factor in our experiment is obtained to be about 3.8 when excited by 350 nm. Our study may have potential applications in polymers optical elements, such as polymer waveguide lasers and amplifiers.

Synthesis of Pt and Pt-Fe nanoparticles supported on MWCNTs used as electrocatalysts in the methanol oxidation reaction

This work reports a feasible synthesis of highly-dispersed Pt and Pt-Fe nanoparticles supported on multiwall carbon nanotubes （MWCNTs） without Fe and multiwall carbon nanotubes with iron （MWCNTs-Fe） which applied as electrocatalysts for methanol electrooxidation. A Pt coordination complex salt was synthesized in an aqueous solution and it was used as precursor to prepare Pt/MWCNTs, Pt/MWCNTs-Fe, and Pt-Fe/MWCNTs using FeC12.4H20 as iron source which were named S 1, S2 and S3, respectively. The coordination complex of platinum （TOA）2PtC16 was obtained by the chemical reaction between （NH4）2PtC16 with tetraoctylammonium bromide （TOAB） and it was characterized by FT-IR and TGA. The materials were characterized by Raman spectroscopy, SEM, EDS, XRD, TEM and TGA. The electrocatalytic activity of Pt-based supported on MWCNTs in the methanol oxidation was investigated by cyclic voltammetry （CV） and chronoamperometry （CA）. Pt-Fe/MWCNTs electrocatalysts showed the highest electrocatalytic activity and stability among the tested electrocatalysts due to that the addition of ＂Fe＂ promotes the OH species adsorption on the electrocatalyst surface at low potentials, thus, enhancing the activity toward the methanol oxidation reaction （MOR）.

Investigation into the effect of silica nanoparticles on the rheological characteristics of water-in-heavy oil emulsions

The effect of silica nanoparticles on the rheological characteristics of water-in-heavy oil emulsions has been investigated.Enhanced oil recovery methods for heavy oil production(most especially,thermal fluid injection)usually result in the formation of water-in-oil(W/O)emulsion.In reality,the emulsion produced also contains some fine solid mineral particles such as silica,which,depending on its quantity,may alter the viscosity and/or rheological properties of the fluid.A series of binary-component emulsions were separately prepared by dispersing silica nanoparticles[phase fraction,βs,=0.5%–5.75%(wt/v)]in heavy oil(S/O suspension)and by dispersing water[water cut,θw=10%–53%(v/v)]in heavy oil(W/O emulsion).Ternary-component emulsions comprising heavy oil,water droplets and suspended silica nanoparticles(S/W/O)were also prepared with similar ranges ofθw andβs.The viscosity was measured at different shear rates(5.1–1021.4 s-1)and temperatures(30–70°C).Both binary-component and ternary-component emulsion systems were observed to exhibit nonNewtonian shear thinning behaviour.The viscosity of the heavy oil and W/O emulsions increased in the presence of silica nanoparticles.The effect was,however,less signifi cant belowβs=2%(wt/v).Moreover,a generalized correlation has been proposed to predict the viscosity of both binary-component and ternary-component emulsions.

Photo-Induced DNA-Dependent Conformational Changes in Silver Nanoparticles

The goal of the present investigation is to study the interaction of AgNPs with thymus DNA by traditional and original spectra-photometric and thermo-dynamic methods and approaches in darkness and under photo-irradiation. 1) At the interaction of DNA with nano-particles hypsochromic shift of 6 nm and hypochromic effect of 20% of AgNPs absorption band are observed. 2) At photo-irradiation (λ = 436 nm or full spectrum of visible band) of AgNPs-DNA complexes absorption spectra band width is changed from 140 nm to 360 nm at half-height. Besides, isosbestic point is observed. 3) Kinetic study of photo-diffusion has made it possible to determine desorption rate constant and desorption reaction activation energy that are equal respectively to kd @ 9 ′ 10-5 s-1, Ed @ 80 kJ/M Ag0 for AgNPs bound with DNA. It is shown that AgNPs represent liquid drops which moisture the DNA surface at interaction. At photo-irradiation of AgNPs-DNA complex DNA dependant conformational transition takes place due to fast and intensive heating.

Synthesis and Characterization of Copper Nanoparticles by Bis-(Acetylacetonato)-Copper (II) Using Nonionic Surfactants and the Effect of Their Structures on Nanoparticles Size and Yield

Between all precursors of copper complex, bis-(acetylacetonato)-copper (II) and bis-oxalate copper (II) with very close structures are two of the best representatives for copper nanoparticles synthesis. In this research, only bis-(acetylacetonato)-copper (II) in presence of some effective non-ionic surfactants such as Triton X-100, Dodecylamine, Tween 80 and also triphenylphosphine as a reducing agent via thermal decomposition process was used for copper nanopaticles synthesis. Two shif-base E19 and E22 complexes were also used for the investigation of these kinds of shif-base complexes capabilities by this method as precursors and all results were compared with each other. Between all surfactants, Triton X-100 gave the best yield with the largest grains. The techniques used for characterization of copper nanoparticles were TEM, EDX, FT-IR and XRD. TG-DTA and CV were used for characterization of bis-(acetylacetonato)-copper (II) complex.

Mg-Sn型复合纳米粒子的摩擦学和磨损修复性能

采用化学方法制备了Mg-Sn型复合纳米添加剂,分别采用四球摩擦磨损试验机和环-块摩擦磨损试验机考察了其作为矿物油添加剂的抗磨减摩性能及对磨损表面的修复作用。采用扫描电子显微镜、粗糙度测定仪及X-射线光电子能谱仪等对摩擦副磨损表面进行了分析,并探讨了其抗磨减摩作用机理。结果表明,Mg-Sn型复合纳米添加剂具有优良的减摩抗磨性能,且对磨损表面具有一定的修复作用。其原因在于,Mg-Sn型复合纳米添加剂在摩擦表面沉积,并在接触区的高温高压作用下熔融铺展,形成低剪切强度的表面膜。由于这层膜的剪切强度比较低,可以减少摩擦界面的黏着磨损,故表现出良好的减摩抗磨和自修复性能。

Designing macrophage membrane-engineered ruthenium/selenium nanoparticles to block bone metastasis of breast cancer

Bone metastasis along with osteolysis is a common complication of advanced breast cancer,which directly destroys bone function and becomes one of the major causes of cancer-related mortality.It is crucial to develop a new strategy to achieve effective cancer therapy and inhibition of osteolytic bone metastasis.Metal ruthenium(Ru)complexes exhibit therapeutic potential in cancer chemotherapy.However,the clinical applications of Ru complexes were limited by poor bioavailability,lacking targeting,nonspecific distribution.Therefore,in this study,engineering of cell membrane biomimetic modification was used to construct a highly biocompatible nanoplatform with carrying Ru metal complex of RuPOP and Se nanoparticles(SeNPs).Strikingly,the obtained RPSR nanoparticles can efficiently inhibit the proliferation,invasion and migration of breast cancer cells(MDA-MB-231 cells)in vitro.More importantly,RPSR nanoparticles can induce cycle arrest,apoptosis by generating excessive intracellular(reactive oxygen species,ROS)to disrupt the normal redox balance and induce DNA damage in tumor cells.Furthermore,RPSR nanoparticles can also reshape bone microenvironment by regulating selenoproteins to inhibit osteoclasts and avoid osteolytic bone metastasis induced by tumor development.Taken together,this study not only provides an effective cell membrane biomimetic strategy to enhance the shortcomings of metal complexes,but also demonstrates potential clinical significance for the combined treatment of anti-cancer and bone metastasis inhibition.

含银离子的聚电解质复合纳米粒子的制备

由分子间弱相互作用驱动的超分子组装受到广泛关注,其中通过静电相互作用组装形成的聚电解质复合物在许多生物化学过程中起着重要的作用,具有潜在的应用价值。通过开环聚合(ROP)和后修饰的方法制备了一系列含羧酸的均聚类肽电解质聚(N-烯丙基甘氨酸)(PNAG-COOH)和(聚(N-炔丙基甘氨酸)PNPG-(COOH)_(2))。该均聚类肽在水溶液中可以通过静电相互作用与银离子共组装形成纳米尺度的聚电解质复合粒子结构。系统研究了电荷比及侧链羧基数目对组装形貌的影响。进一步在聚电解质复合体系中加入抗坏血酸,将体系中的银离子原位还原为单质银,得到尺寸均匀分散的银纳米粒子。

Low-Molecular-Weight Heparin and Protamine-Based Polyelectrolyte Nano Complexes for Protein Delivery (A Review Articles)

We produced low-molecular-weight heparin/protamine micro (nano) particles (LMW-H/P MPs·NPs) as a carrier for heparin-binding growth factors (GFs), such as fibroblast growth factor (FGF)-2 and various GFs in platelet-rich plasma (PRP). A mixture of LMW-H (MW: approximately 5000 Da, 6.4 mg/ml) and protamine (MW: approximately 3000 Da, 10 mg/ml) at a ratio of 7:3 (vol:vol) yields a dispersion of micro (nano) particles (200 nm - 3 μm in diameter). The diluted LMW-H solution in saline (0.32 mg/ml) mixed with diluted protamine (0.5 mg/ml) at a ratio at 7:3 (vol:vol) resulted in soluble nanoparticles (approximately 100 nm in diameter). The generated NPs could be then stabilized by adding 2 mg/ml dextran (MW: 178-217 kDa) and remained soluble after lyophilization of dialyzed LMW-H /P NPs solution. The LMW-H/P MPs·NPs adsorb GFs, control their release, protect GFs and activate their biological activities. Furthermore, administration of GFs-containing F/P MPs·NPs exhibited significantly higher inductions of vascularization and fibrous tissue formation in vivo than GFs alone. LMW-H/P MPs·NPs can also efficiently bind to tissue culture plates and retain the binding of GFs. The LMW-H/P MPs·NP-coated matrix with various GFs or cytokines provided novel biomaterials that could control cellular activity such as proliferation and differentiation. Thus, LMW-H/P MPs·NPs are an excellent carrier for GFs and are a functional coating matrix for various kinds of cell cultures.

Synthesis of ultrafine copper particles by complex-reduction-extraction method

A novel chemical process for producing well-defined copper particles with satisfied anti-oxidation property was described. The resultant particles were characterized by X-ray diffractometry and scanning electron microscopy. The results show that well-dispersed nano-copper particles with 70 nm in diameter are obtained from the water/organic solution containing 0.2 mol/L Cu2+ ion,with ammonia as ligand and ascorbic acid as reductant. In this process,the formation of copper-ligands in aqueous solution causes initial copper ions concentration very low,which is not only good to obtain homogeneous initial reaction solution,but also slower the initially drastic nucleation reaction rate. This makes the process more convenient for delaying the nuclei processes and for controlling the ultimate copper particles size. In addition,oleic acid acts as both a phase-transfer agent and a particle protector coordinating their carboxyl end groups on the new generated copper particles surface,the carbon tails of the oleic acids are pointed outwards from the surface of the synthesized particles. This organic film also seems to play an important role to prevent the new generated copper particles from oxidation.

Fabrication and Characterisation of Novel Natural Lycopodium clavatum Sporopollenin Microcapsules Loaded In-Situ with Nano-Magnetic Humic Acid-Metal Complexes

Sporopollenin exines microcapsules, derived from the naturally occurring spores of Lycopodium clavatum, have been loaded in-situ with humic acid sodium salt-Zinc (HA-Zn) complex. The chemical treatment method utilised to prepare the sporopollenin microcapsules from raw spores was discussed and the resulted sporopollenin microcapsules were characterised using SEM, TGA and FTIR. Metal complexes of the sodium salt of humic acid and zinc ion were prepared using different protocols and in-situ loaded into the pre-treated sporopollenin microcapsules. The resulted complex was characterised before and after the encapsulation process using FTIR, TGA and XRD techniques. The morphology of the empty and loaded sporopollenin was not altered. Infrared spectroscopy revealed an increase in the absorption for COO– vibrations at 1583 and 1384 cm–1 in the FTIR spectra of HA-Zn complex compared to that of the original sodium salt of humic acid, indicative of bonding of the metal ions in hydrated form to the carboxyl or phenolic hydroxyl groups or both of the sodium humate molecules. TGA results of the HA-Zn complex loaded sporopollenin showed that around %15 of residual HA-Zn was successfully encapsulated indicative of the efficiency of the protocol used. We showed also that biodegradable magnetite nanoparticles can be surface modified with HA and encapsulated into sporopollenin. The resulted biosorbents microcapsules can be used for enhanced magnetic removal of either heavy metals or HA from different aqueous media.