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Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive malignancies. TGF-β is strongly expressed in both the epithelial and stromal compartments of PDAC, and dysregulation of TGF-β signalling is a frequent molecular disturbance in PDAC progression and metastasis. In this study, we investigated whether blockade of TGF-β signalling synergizes with nal-IRI/5-FU/LV, a chemotherapy regimen for malignant pancreatic cancer, in an orthotopic pancreatic tumour mouse model. Compared to nal-IRI/5-FU/LV treatment, combining nal-IRI/5-FU/LV with vactosertib, a TGF-β signalling inhibitor, significantly improved long-term survival rates and effectively suppressed invasion to surrounding tissues. Through RNA-sequencing analysis, we identified that the combination treatment results in robust abrogation of tumour-promoting gene signatures and positive enrichment of tumour-suppressing and apoptotic gene signatures. Particularly, the expression of tumour-suppressing gene Ccdc80 was induced by vactosertib and further induced by vactosertib in combination with nal-IRI/5-FU/LV. Ectopic expression of CCDC80 suppressed migration and colony formation concomitant with decreased expression of epithelial-to-mesenchymal transition (EMT) markers in pancreatic cancer cells. Collectively, these results indicate that combination treatment of vactosertib with nal-IRI/5-FU/LV improves overall survival rates in a mouse model of pancreatic cancer by suppressing invasion through CCDC80. Therefore, combination therapy of nal-IRI/5-FU/LV with vactosertib could provide clinical benefits to pancreatic cancer patients.

Magnetic nanoparticles biofunctionalized with antibodies against β-amyloid-40 (Aβ-40) and Aβ-42, which are promising biomarkers related to Alzheimer's disease (AD), were synthesized. We characterized the size distribution, saturated magnetizations, and stability of the magnetic nanoparticles conjugated with anti-Aβ antibody. In combination with immunomagnetic reduction technology, it is demonstrated such biofunctionalized magnetic nanoparticles are able to label Aβs specifically. The ultralow-detection limits of assaying Aβs in vitro using the magnetic nanoparticles via immunomagnetic reduction are determined to a concentration of ∼10 ppt (10 pg/mL). Further, immunomagnetic reduction signals of Aβ-40 and Aβ-42 in human plasma from normal samples and AD patients were analyzed, and the results showed a significant difference between these two groups. These results show the feasibility of using magnetic nanoparticles with Aβs as reagents for assaying low-concentration Aβs through immunomagnetic reduction, and also provide a promising new method for early diagnosis of Alzheimer's disease from human blood plasma.

Several methods have been described to introduce DNA expression vectors into mammalian cells both in vitro and in vivo. Each system has benefits and limitations, and to date there is still no ideal method for gene transfer. In this study, we introduced a novel method of gene transfer by using Fe3O4 nanoparticles. The magnetic nanoparticles composed of Fe3O4, and the transfected genes used are Lac Z and enhanced green fluorescence protein gene (EGFG). Four different groups of preparations included in this study were homemade liposome-enveloped EGFP-DNA/Fe3O4, homemade liposome EGFP-DNA gene without magnetic Fe3O4 nanoparticles, lipofectamine 2000-enveloped EGFP-DNA, and EGFP-DNA gene only. Mice osteoblast and He99 lung cancer cell line were used as host cells for gene transfection. The time-dependent EGFP gene expression was monitored and analyzed. The results showed that the diameter of the complex was less than 100 nm. There was no cytotoxicity observed at any of the magnetic Fe3O4 nanoparticle concentrations tested. In the presence of magnetic field, the liposome-enveloped EGFP-DNA/Fe3O4 complex exhibited a much higher efficiency for transfecting EGFP-DNA into osteoblast cells under external magnetic fields. The gene can be transfected into cells with an aid of magnetic vectors and magnetic force. Under a gradient magnetic field, the efficiency of magnetofection is enhanced as compared to that without magnetic field.

Via immunomagnetic reduction assay, biomolecules can be quantitatively detected with aid of biofunctionalized magnetic nanoparticles, which are used as labeling markers for specific biomolecules. To achieve ultra-high sensitivity in detecting biomolecules, superconducting quantum interference device (SQUID) is a promising candidate to act as a sensor to the magnetic signal related to the concentration of detected biomolecules. In the past, we developed a single channel SQUID-based magnetosusceptometry. In order to increase the detection through-put, multichannel SQUID-based magnetosusceptometry is developed. In this work, the design and working principle of four-channel SQUID-based magnetosusceptometry are introduced. Using utilizing scanning technology, four samples can be simultaneously logged into the SQUID-based magnetosusceptometry. Notably, only single SQUID magnetometer is used in the magnetosusceptometry. The precision and sensitivity in detecting biomolecules using the four-channel SQUID-based magnetosusceptometry are investigated. [ABSTRACT FROM AUTHOR]

Graphical abstract Heterostructured CdS/BiVO 4 nanocomposites with thinner BiVO 4 nanosheets exhibit enhanced photocatalytic activity for CO 2 reduction. Highlights • CdS/BiVO 4 composites are prepared by loading CdS nanoparticles on BiVO 4 nanosheets. • CdS/BiVO 4 nanocomposites exhibit enhanced photocatalytic activity for CO 2 reduction. • Yields of products CH 4 and CO vary depending on the thickness of BiVO 4 substrate. • Improved photocatalytic activity is ascribed to Z-scheme charge transfer mode. Abstract Construction of Z-scheme photocatalysts has drawn much attention in the field of CO 2 reduction. However, research on photoreduction CO 2 for monoclinic bismuth vanadate (m -BiVO 4) is restricted due to its low conduction band potential and short electron diffusion lengths. To address the issues, we herein constructed a series of CdS/BiVO 4 nanocomposites by depositing CdS on the surface of BiVO 4 coupling with controlling the thickness of BiVO 4 nanosheets. The morphological, crystalline, band alignment and optical properties of the samples are investigated intensively. Photocatalytic performance is evaluated by measuring the ability of the photocatalysts to convert CO 2 into CO and hydrocarbon fuels, primarily CH 4. The composites exhibit more efficient photocatalytic activity than CdS and BiVO 4 , and the yields of CH 4 and CO vary depending on the thickness of BiVO 4 substrate. The maximum yields of CH 4 and CO for CdS/BiVO 4 with 55–75 nm BiVO 4 are 2.98 and 1.31 μmol g−1 after 5 h irradiation, while those for its counterpart with 15–30 nm BiVO 4 attain 8.73 and 1.95 μmol g−1, respectively. The enhanced photoactivity of the composites is attributed to the band structure and Z-scheme charge transfer mode. Besides, thinner BiVO 4 nanosheets are confirmed to be favorable for improving the photoreduction CO 2 efficiency due to shorter electron diffusion lengths. [ABSTRACT FROM AUTHOR]

Quaternary kesterite-type Cu2ZnSnS4 (CZTS) nanoparticles (NPs) were successfully synthesized by a single-step solvothermal process. Semiconductor CZTS nanoparticles were obtained from ethylene glycol (EG) and CZTS precursor after solvothermal process at 180 °C for 30 h in polyvinylpyrrolidone (PVP) medium. The synthesized CZTS NPs were further annealed at 450 °C in nitrogen atmosphere and used for further characterizations. The CZTS NPs were characterized using X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), micro Raman spectroscopy, high resolution transmission electron microscopy (HRTEM) and X-ray photoelectron spectroscopy (XPS). The optical properties of the CZTS NPs were recorded by UV-vis absorption spectroscopy. The results showed that the synthesized CZTS nanoparticles are kesterite-type CZTS, with good crystallinity and a stoichiometric composition. Moreover, the prepared nanoparticles have a size ranging from 5-7 nm and a band gap of ∼1.5 eV. [ABSTRACT FROM AUTHOR]

With antibody-mediated magnetic nanoparticles (MNPs) applied in cancer examinations, patients must pay at least twice for MNP reagents in immunomagnetic reduction (IMR) of in vitro screening and magnetic resonance imaging (MRI) of in vivo tests. This is because the high maintenance costs and complex analysis of MRI have limited the possibility of in vivo screening. Therefore, this study proposes novel methods for in vivo screening of tumors by examining the AC susceptibility of bound MNPs using scanning superconducting-quantum-interference-device (SQUID) biosusceptometry (SSB), thereby demonstrating high portability and improved economy. The favorable agreement between in vivo tests using SSB and MRI demonstrated the feasibility of in vivo screening using SSB for hepatocellular carcinoma (HCC) targeted by anti-alpha fetoprotein (AFP)-mediated MNPs. The magnetic labeling was also proved by in vitro tests using SSB and biopsy assays. Therefore, patients receiving bioprobe-mediated MNPs only once can undergo in vivo screening using SSB in the future. [ABSTRACT FROM AUTHOR]

We investigated the relaxation of protons in magnetic fluids using a high-Tc SQUID magnetometer. It was found that the longitudinal relaxation rate, 1/T1, is slower than the transverse relaxation rate, 1/T2, for ferrofluids in the same field. This is due to the fact that the 1/T1 process involves returning the magnetization to the z-direction, which automatically involves the loss of magnetization in the x-y plane governed by the 1/T2 process. Additionally, 1/T1 and 1/T2 at high temperatures are slower than the corresponding relaxation rates at low temperatures, which is due to the enhanced Brownian motion of nanoparticles at high temperatures. [ABSTRACT FROM AUTHOR]

Abstract: Nanoscale 8 mol% yttria stabilized zirconia (YSZ) powders were prepared by polyethylene glycol (PEG-1540) assisted coprecipitation coupling with azeotropic distillation drying process. The role of PEG and azeotropic-distillation on the morphology and particle size of YSZ was studied. Thermogravimetry and X-ray diffraction results showed that azeotropic-distillation could reduce the formation temperature of YSZ phase. X-ray patterns of the YSZ powders revealed that the crystallite size of the powders increases with increasing calcination temperature, which is consistent with transmission electron microscopy observations. The sintering behavior and the ionic conductivity of the pellets prepared from YSZ powders calcined at 800°C were also studied. At sintering temperatures ≥1400°C, more than 99% of the relative density was obtained. The alternating-current impedance spectroscopy results showed that the YSZ pellet sintered at 1450°C has ionic conductivity of 0.0726Scm−1 at 800°C in air. The present work results have indicated that the PEG assisted coprecipitation combined with azeotropic-distillation drying process is an alternative method to synthesize yttria stabilized zirconia powders with a high sinterability and a good ionic conductivity. [Copyright &y& Elsevier]

Abstract: Highly dispersible zinc oxide nanoparticles were produced in large quantity via a simple solution method. The effect of temperature and pH impact on as-prepared ZnO nanoparticles with respect to the morphological and optical characteristics has been investigated. The average particle size of ZnO nanoparticles increased with increasing annealing temperature. A sharp UV band-edge emission was observed in as-prepared ZnO nanoparticles with negligibly less intense deep level emission. However, upon annealing at high temperature in air, UV band-edge emission disappears with an evolution of a broad deep level emission in photoluminescence spectra. Similarly, by adjusting the pH of reaction medium from 4 to pH=8 using ammonium hydroxide solution, particle size gets bigger and bigger leads to red-shift in UV band-edge emission and an appearance of deep level emission peak. At pH=8, well resolved sharp X-ray diffraction peaks were observed with lower FWHM values due to higher crystallite sizes. [Copyright &y& Elsevier]

Several methods have been described to introduce DNA expression vectors into mammalian cells both in vitro and in vivo. Each system has benefits and limitations, and to date there is still no ideal method for gene transfer. In this study, we introduced a novel method of gene transfer by using Fe3O4 nanoparticles. The magnetic nanoparticles composed of Fe3O4, and the transfected genes used are Lac Z and enhanced green fluorescence protein gene ( EGFG). Four different groups of preparations included in this study were homemade liposome-enveloped EGFP–DNA/Fe3O4, homemade liposome EGFP–DNA gene without magnetic Fe3O4 nanoparticles, lipofectamine 2000-enveloped EGFP–DNA, and EGFP–DNA gene only. Mice osteoblast and He99 lung cancer cell line were used as host cells for gene transfection. The time-dependent EGFP gene expression was monitored and analyzed. The results showed that the diameter of the complex was less than 100 nm. There was no cytotoxicity observed at any of the magnetic Fe3O4 nanoparticle concentrations tested. In the presence of magnetic field, the liposome-enveloped EGFP–DNA/Fe3O4 complex exhibited a much higher efficiency for transfecting EGFP–DNA into osteoblast cells under external magnetic fields. The gene can be transfected into cells with an aid of magnetic vectors and magnetic force. Under a gradient magnetic field, the efficiency of magnetofection is enhanced as compared to that without magnetic field. [ABSTRACT FROM AUTHOR]

Developing high-efficiency electrocatalysts viable for pH-universal hydrogen evolution reaction (HER) has attracted great interest because hydrogen is a promising renewable energy carrier for replacing fossil fuels. Herein, we present a facile strategy for fabricating ultra-fine Ru nanoparticles (NPs) decorated V 2 O 3 on the carbon cloth substrates as efficient and stable pH-universal catalysts for HER. Benefiting from the metallic property and electronic conductivity of V 2 O 3 matrix, the optimized hybrid (Ru/V 2 O 3 -CC) exhibits excellent HER activities in a wide pH range, achieving lower overpotentials of 184, 219, and 221 mV at 100 mA cm−2 in 0.5 M H 2 SO 4 , 1.0 M KOH and 1.0 M phosphate-buffered saline, respectively. Moreover, the electrode remains superior stability with negligible degradation after 5000 cyclic voltammetry scanning whether in acidic, alkaline or neutral media. Experimental results, combined with theoretical calculations, demonstrate that the interaction between Ru NPs and the support V 2 O 3 induces the local electronic density diversity, allowing optimization of the adsorption energy of Ru towards hydrogen intermediate H∗, thus favoring the HER process. The well-designed Ru/V 2 O 3 -CC electrocatalyst exhibits a high-efficient and pH-universal HER property, which is attributed to the ample active sites of ultrafine Ru NPs and good electronic transmission property of inert V 2 O 3. [Display omitted] • The fabricated Ru/V 2 O 3 -CC exhibits superior activity viable for pH-universal HER. • The electron transfer is optimized by introducing ultrafine Ru NPs on V 2 O 3. • V 2 O 3 modulates the electronic environment around Ru NPs and optimizes ΔG H∗ of Ru. [ABSTRACT FROM AUTHOR]

Abstract: A simple solution method has been proposed that deals the specific impacts of solvent characteristics on the growth of zinc oxide (ZnO) nanoparticles. The aggregation of particles is a major drawback in the hydrothermal method, and it is suppressed by using a less polar reaction solvent. ZnO particles obtained from a lower polarity indexed reaction medium show a very strong UV band-edge emission with an almost negligible deep level emission when compared to ZnO particles isolated from the higher polarity index of the medium. For the application is concerned, highly dispersible ZnO nanomaterials are used as an active material for dye-sensitized solar cells (DSSC), due to their higher internal surface area. Additionally, the deposition of ZnO layers on commercially available GaN-based blue light emitting diodes (LEDs) is fabricated to improve the light extraction efficiency, without disturbing the basic structure of the LED. The layer thickness and light transmission at a specific wavelength are the major factors which can improve the light emission from LEDs. [Copyright &y& Elsevier]

Abstract: We performed an investigation of amorphous tris(8-hydroxyquinoline)aluminum (Alq3) molecules transferred into α-phase crystalline nanomaterials by incorporating a few weight percentage of crystalline zinc oxide (ZnO) nanoparticles. Various shapes of hybrid Alq3–ZnO nanomaterials were synthesized from a one-step solution method at relatively very low temperature. We examined the effect of temperatures and the amount of incorporated ZnO nanoparticles on the evolution of morphologies of hybrid nanomaterials by using field emission scanning electron microscopy. Photoluminescence (PL) spectra of hybrid nanomaterials containing 15 and 25% of ZnO showed a three and five-fold enhancement in PL intensity, respectively, over the pure Alq3 molecules. We attributed the achievement of higher PL intensity of Alq3–ZnO hybrids to the incorporation of crystalline ZnO nanoparticles. This incorporation allowed for energy transfer from ZnO particles and occurrence of caging effect of ZnO nanoparticles thus avoiding excimer formation between Alq3 molecules in the excited state. A blue-shift in the PL emission of the hybrid nanomaterials resulted, with respect to ZnO content, due to the quantum confinement effect of the ZnO nanoparticles. [Copyright &y& Elsevier]

Co nanoparticles supported on three-dimensionally (3D) N-doped holey graphene aerogels (Co/N-GA-h) hybrids were successfully synthesized by simple high-temperature pyrolysis method. As a non-noble metal electrocatalyst, the Co/N-GA-h hybrids displayed the excellent activity and durability for the ORR in alkaline media. The reactive and stable catalysts for the oxygen reduction reaction are highly desirable for low temperature fuel cells. The commercial oxygen reduction reaction electrocatalysts generally reply on noble metal based nanomaterials, which suffer from inherent cost and selectivity issues. At present, it still remains challenge for designing efficient non-noble metal-based oxygen reduction reaction electrocatalysts. Herein, we successfully synthesize Co nanoparticles supported on three-dimensionally N-doped holey graphene aerogels hybrids by the high-temperature calcination of the graphene aerogels-polyallylamine-CoII hybrids. The component optimized hybrids show the excellent electrocatalytic activity for oxygen reduction reaction in alkaline media, which is comparable to commercial Pt/C electrocatalyst. Meanwhile, the hybrids also show eminent tolerance for CO and methanol, attributing to their excellent oxygen reduction reaction selectivity. The three-dimensionally interconnected structure of graphene aerogels, N-doping, uniform dispersion and high crystallinity of Co nanoparticles, and holey structure of graphene contribute to the striking oxygen reduction reaction activity of hybrids. [ABSTRACT FROM AUTHOR]

[Display omitted] • Surface compositions of ZnFe 2 O 4 were regulated by alkali treatment. • Surface iron-rich ZnFe 2 O 4 had increased H 2 O adsorption and charge separation. • Photocatalytic H 2 production activity of optimal ZnFe 2 O 4 was significantly enhanced. Photocatalytic water splitting has emerged as a promising avenue for the utilization of solar energy to produce hydrogen. To advance the development of photocatalytic hydrogen production, the optimization and design of novel photocatalysts is a crucial task. In this study, ZnFe 2 O 4 nanoparticles with iron-rich surfaces were synthesized through alkali treatment and employed in photocatalytic water vapor decomposition. The alkali-treated ZnFe 2 O 4 displayed superior photocatalytic activity, with the optimized sample exhibiting an impressive H 2 generation rate of 61.9 μmol·g−1 after 5 h of irradiation, which is significantly higher than the untreated ZnFe 2 O 4 sample (15.9 μmol·g−1). This enhanced performance is attributed to the improved separation of photogenerated carriers and the improved adsorption of water molecules on the iron-rich ZnFe 2 O 4 surface. This research may provide a valuable guide for the design of highly active ternary oxide/sulfide semiconductor photocatalysts for water vapor splitting. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Three–dimensional thermal interface materials made of graphene oxide and copper nanoparticles (GO–Cu NPs) have synthesized. • The effect of the stacking order of GO–Cu NPs on thermal resistance has explored for enhancing LED heat dissipation. • Analysis by a FLIR camera has showed that the combination of GO and Cu NPs enabled heat dissipation properties. • The thermal resistance of the mixed GO–Cu NPs structure is less 37 % than that of the Al heat sink. Abstract Three–dimensional thermal interface materials made of graphene oxide (GO) and copper nanoparticles (Cu NPs) were applied for enhancing light–emitting diode heat dissipation. The effect of the stacking order of GO and Cu NPs on thermal resistance was explored by creating two types of samples: spray–coated with a mixed GO–Cu NPs and layer–by–layer stacked with GO/Cu NPs/GO. A reduction of thermal resistance for mixed GO–Cu NPs and layer–by–layer stacked structure by 37% and 33%, respectively, compared to that of Al heat sink. The lower thermal resistance of the mixed GO–Cu NPs sample is attributed to the fact that distributed Cu NPs at the step edge of GO sheets enhances the out–of–plane heat transfer at wrinkles/folds of GO interlayers. Therefore, a mixed GO–Cu NPs is considered as a promising composite for effective thermal management of high–performance optoelectronic devices. [ABSTRACT FROM AUTHOR]

Development of highly efficient and low-cost noble metal-free co-catalysts for photocatalytic H 2 evolution from water splitting has been aiming at a long-term goal of a renewable hydrogen economy. Herein, a series of novel Mn 0.2 Cd 0.8 S/CoP 3 composites have been successfully prepared through loading CoP 3 nanoparticles on the surface of one dimensional (1D) Mn 0.2 Cd 0.8 S nanowires (NWs) by a facile solvothermal method. Under visible light (λ ≥ 420 nm) irradiation, the as-prepared Mn 0.2 Cd 0.8 S/CoP 3 composite with 2.87 wt% of CoP 3 displayed the highest photocatalytic H 2 evolution activity with a corresponding H 2 evolution rate of 29.53 mmol g −1  h −1 and an apparent quantum yield of 29.2% at 420 nm, which was about 5.02 times higher than that of pure Mn 0.2 Cd 0.8 S and 1.79 times than that of Mn 0.2 Cd 0.8 S/Pt-1.5 wt%. Moreover, the Mn 0.2 Cd 0.8 S/CoP 3 composite exhibited excellent photostability. The superior photocatalytic activity of Mn 0.2 Cd 0.8 S/CoP 3 composite was predominantly attributed to the synergistic effects of highly efficient charge separation efficiency and sufficient active sites for H 2 evolution reaction. This work revealed that low-cost CoP 3 can replace noble metal Pt as a highly efficient co-catalyst for enhancing the photocatalytic activity of semiconductor materials. [ABSTRACT FROM AUTHOR]

The 3D TiO 2 microflowers sensitized by Bi 2 Te 3 nanoparticles such novel nanostructure employed by two step synthesis strategy such as hydrothermal method and potentiostatic electrodeposition technique. Herein we have successfully synthesized Bi 2 Te 3 nanoparticles loaded TiO 2 photoanode for quantum dot-sensitized solar cells (QDSSCs). The combined 3D and 1D hierarchical structure has significant potential as an efficient photoanode for QDSSC. [ABSTRACT FROM AUTHOR]

Abstract: A two-step growth approach based on facet-controlled epitaxial lateral growth and the application of silica nanospheres was established to enhance the performance of GaN based light-emitting diodes (LEDs). In the first step, open inverted honeycomb cones (IHCs) were fabricated. These IHCs were filled with silica nanospheres and a second growth step was performed. As compared to LEDs fabricated on IHC templates, 2.7 fold electroluminescence (EL) intensity was obtained for silica nanospheres-stacked IHC due to improved crystal quality and light scattering at silica nanospheres. Simulation of emission intensity was carried out to determine the effect of dislocation density reduction on EL enhancement of the LEDs. [Copyright &y& Elsevier]

Abstract: In this article, we focused on cadmium sulphide (CdS) nanoparticles (NPs) sensitized rutile TiO2 microspheres (TMS) as a photoanode, which has been studied systematically. Hydrothermally grown TMS are sensitized with CdS NPs by simple and cost effective successive ionic layer adsorption and reaction (SILAR) technique. The synthesized CdS and CdS-TMS samples were characterized by Fourier Transform Raman Spectroscopy (FT-Raman), X-ray photoelectron spectroscopy (XPS) and FESEM characterization techniques. The CdS and CdS-TMS samples were further used for their photoelectrochemical (PEC) performance and were tested in Na2Slyph name="sbnd" />S and Na2S electrolytes respectively. When CdS nanoparticles are coated on TMS, it exhibits improved photoelectrochemical (PEC) performance with maximum short circuit current of (JSC) 2.75mA/cm2. The Judiciously optimized CdS-decorated TiO2 morphology will be helpful for effective light-harvesting and fast electron-transfer from CdS to conduction band (CB) of TiO2. The highest power conversion efficiency of semiconductor-sensitized solar cells (SSSCs) i.e. CdS NP-sensitized TMS for the first time is 2.34% which is much higher than the bare CdS sample. [Copyright &y& Elsevier]

Abstract: Different types of zinc oxide (ZnO) materials such as micro-rods, textured, nanoparticles and nanorods have been synthesized as photoanodes via a simple method for dye-sensitized solar cells (DSSCs). The relationship between the optical transparency and the device efficiency has been correlated with respect to film thickness. The maximum conversion efficiency is recorded from the device containing slantingly grown ZnO nanorods. Besides, the lower conversion efficiency is obtained from the device with ZnO micro-rods. A plausible schematic diagram is drawn to explain the reason for the higher power conversion in slantingly grown ZnO nanorods over the well-aligned nanorods. [Copyright &y& Elsevier]

Abstract: Highly transparent ZnO nanomaterials have been successfully dispersed in the form of nanoparticles and nanorods on InGaN/GaN-based surface mounted light emitting diodes (SM-LEDs). An effortless spin-coating technique is employed to disperse the ZnO nanoparticle layers, and a well-known hydrothermal technique is used for growing the ZnO nanorods. The layer thickness and the light transmission at a specific wavelength are the major factors in improving the light output power of the devices. Field emission scanning electron microscope (FESEM) images are used to confirm the uniform dispersion of the ZnO nanostructures on the top of the SM-LEDs. The layer thickness and the level of light transmission at 460nm are examined from the cross-sectional FESEM images and UV absorption spectra, respectively. [ABSTRACT FROM AUTHOR]

Abstract: The effects of the nitric acid (HNO3) treatment of TiO2 nanoparticles on the photovoltaic properties of the dye-sensitized solar cell (DSSC) were investigated. The HNO3 treatment enhanced the dispersion of TiO2 particles, increased the surface area and porosity of the sintered TiO2 films, increased the relative proportion of the Ti3+ state in the Ti 2p X-ray photoelectron spectroscopy spectrum, significantly increased the amount of adsorbed dye molecules on the TiO2 electrode, and reduced the charge-transfer resistance at the TiO2/dye/electrolyte interface. The short circuit photocurrent density (I sc) was increased due to the increased amount of adsorbed dye molecules and the reduced charge-transfer resistance. The HNO3 pre-treatment of TiO2 particles improved the overall conversion efficiency of the DSSC by about 14%. [Copyright &y& Elsevier]

Abstract: An incorporation of few weight percentage of n-type zinc oxide (ZnO) on the surface of yellow-emitting fluorescent polymer under mild conditions was demonstrated. Here, a deep level emissive ZnO was selectively deposited on the surface of fluorescent polymer via a simple chemical deposition bath method, at relatively low temperature. The polymer–zinc oxide hybrids, consisting of uniform nanosized spherical fluorescent polymer, having mean diameter ca. ∼500–700nm were subjected as core molecules capped with different weight ratio of ZnO on the surfaces were prepared successfully. The relative photoluminescence emission efficiency was drastically enhanced as two-fold with just 4wt% of ZnO incorporation and also more than 10-fold improvement in 50wt% of ZnO content with respect to pure fluorescent polymer. Bright and efficient white light-emitting devices have been fabricated with these hybrid materials, such as luminescence converter light-emitting diodes (LUCO LEDs), using commercially available GaN LED (460nm), as a primary pumping source. A device containing 20wt% of ZnO incorporated hybrid material (2wt%) exhibits nearly pure white light, having Commission Internationale de I’Eclairage coordinates of (0.30,0.36) and total luminous flux of 1.80lm, at an operating voltage of 20mA. The lifetime measurement data of fabricated device containing polymer–ZnO hybrid materials showed significant improvements over the pure counterpart, due to the “caging effect” of the ZnO shell, which can reduce the self-quenching of the polymer molecules in the core. [Copyright &y& Elsevier]

Abstract: ZnO nanoparticles were synthesized in a simple solution route without assistance of base, surfactant, template etc., at relatively very low temperature, by a single-step process. The growth rate was greatly controlled by the presence of water-immiscible non-polar solvent, which led to formation of almost pure ZnO nanoparticles with near UV emission. On the other hand, water-miscible polar solvent generates fully defected deep-level emissive ZnO nanoparticles, which agglomerate on standing due to the solvent homogeneity in the reaction mixture. The growth mechanism of ZnO nanoparticles is discussed based on the effect of solvent polarity and water miscibility with respect to particle growth rate. The structural information provided by XRD, Raman scattering, FE-SEM, TEM, and PL spectra confirms the validity of proposed growth mechanism for the ZnO nanoparticles. The experimental results reveal that the ZnO crystal growths are more sensitive to the mixture of solvents, which depends on the miscibility, polarity, and homogeneity of precursor in the reaction medium. [Copyright &y& Elsevier]

The second near-infrared (NIR-II) fluorescence probes present many advantages for its large Stokes-shift and low signal to noise ratio. Lanthanide doped NIR-II luminescent nanoparticles have attracted intense attention in biomedical research. Here Er3+ doped nanoparticles with core–shell structure were proposed. After surface modification, we got PEG modified hydrophilic NaYbF 4 :Er@CaF 2 nanoparticles. The cytotoxicity test and the imaging performance in vivo experiments were carried out. Under the irradiation of 980 nm laser, the mice presented clear near-infrared imaging in vivo. So far, prominent optical properties of NaYbF 4 :Er@CaF 2 -PEG UCNPs have been proved, which is expected to become a new type of imaging probe in the future. • The optimized concentration of Er3+ for bright NIR-II luminescence in NaYbF 4 :Er@CaF 2 was 5%. • Core-shell structure made Er3+ ions have largely enhanced fluorescence both at NIR and UCL region. • The luminescent images of living mice showed high signal-to-noise in NIR mode than upconversion mode. The second near-infrared (NIR-II) fluorescence probes presents many advantages for its large Stokes-shift and low signal to noise ratio. Lanthanide doped NIR-II luminescent nanoparticles have attracted intense attention in biomedical research. Here Er3+ doped nanoparticles with core–shell structure was proposed. After surface modification, we got PEG modified hydrophilic NaYbF 4 :Er@CaF 2 nanoparticles. The cytotoxicity test and the imaging performance in vivo experiments were carried out. Under the irradiation of 980 nm laser, the mice presented clear near-infrared imaging in vivo. So far, prominent optical properties of NaYbF 4 :Er@CaF 2 -PEG UCNPs has been proved, which is expected to become a new type of imaging probe in the future. [ABSTRACT FROM AUTHOR]

Abstract: We report on the spectral tunability of white light by localized surface plasmon (LSP) effect in a colour converting hybrid device made of CdSe/ZnS quantum dots (QDs) integrated on InGaN/GaN blue light-emitting diodes (LEDs). Silver (Ag) nanoparticles (NPs) are mixed with QDs for generating LSP effect. When the plasmon absorption of Ag NPs is synchronized to the QW emission at 448nm, the NPs selectively absorb the blue light and subsequently enhance the QD emission. Using this energy transfer scheme, the (x, y) chromaticity coordinates of the hybrid white LED was tuned from (0.32,0.17) to (0.43,0.26), and thereby generated warm white light emission with correlated colour temperature (CCT) around 1800K. Moreover, a 47% enhancement in the external quantum efficiency (EQE) was realized. [Copyright &y& Elsevier]

• Novel biotemplated top-down assembly of Ni-based catalyst by the low-cost material and simple controllable process. • Well-dispersed Ni nanoparticle reduced from nickel silicate by in-situ pyrolysis of polyaniline layer. • The synergistic effect of well-dispersed Ni nanoparticles and N doping carbon layer for enhancing catalytic activity. • The DE/Ni/N-C-800 exhibited excellent catalytic activity and good stability in ten cycles. Biotemplated top-down assembly of hybrid Ni nanoparticles/N doping carbon on diatomite (DE/Ni/N-C) was synthesized and used to catalytically reduce 4-nitrophenol (4-NP) solution in presence of NaBH 4. The uniform nickel silicate nanosheets uniformly grown on the diatomite with maintained porous structure, enlarging the specific surface area. The thin polyaniline layer was then controllably coated on the nickel silicate nanosheets. The well-dispersed Ni nanoparticles with mean diameter of 20.3 nm were reduced from nickel silicate nanosheets by carbon from polyaniline pyrolysis process. Meanwhile, the N doping carbon layer was in-situ generated outside of the Ni nanoparticles. In the catalytic reduction of 4-NP reaction, the DE/Ni/N-C-800 exhibited excellent catalytic activity with activity parameter 0.053 mg−1 s−1 and stability after ten cycles. The presented results show an enhanced catalytic behavior of the DE/Ni/N-C-800 prepared by the low-cost material and simple controllable process, which indicates their potential for environmental remediation applications. [ABSTRACT FROM AUTHOR]