Enhancement of photoluminescence intensity of erbium doped silica containing Ge nanocrystals: distance dependent interactions

Photo-physical processes in Er-doped silica glass matrix containing Ge nanocrystals prepared by the sol–gel method are presented in this article. Strong photoluminescence at 1.54 μ m, important for fiber optics telecommunication systems, is observed from the different sol–gel derived glasses at room temperature. We demonstrate that Ge nanocrystals act as strong sensitizers for Er 3+ ions emission and the effective Er excitation cross section increases by almost four orders of magnitude with respect to the one without Ge nanocrystals. Rate equations are considered to demonstrate the sensitization of erbium luminescence by Ge nanocrystals. Analyzing the erbium effective excitation cross section, extracted from the flux dependent rise and decay times, a Dexter type of short range energy transfer from a Ge nanocrystal to erbium ion is established.

S Manna, R Aluguri, R Bar, S Das, N Prtljaga, L Pavesi and S K Ray

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Curcumin-incorporated albumin nanoparticles and its tumor image

Albumin is an ideal carrier for hydrophobic drugs. This paper reports a facile route to develop human serum albumin (HSA)–curcumin (CCM) nanoparticles, in which β -mercaptoethanol ( β -ME) acted as an inducer and CCM acted as a bridge. Fluorescence quenching and conformational changes in HSA–CCM nanoparticles occurred during assembly. Disulfide bonds and hydrophobic interactions may play a key role in assembly. HSA–CCM nanoparticles were about 130 nm in size, and the solubility of CCM increased by more than 500 times. The HSA–CCM nanoparticles could accumulate at the cytoplasm of tumor cells and target the tumor tissues. Therefore, HSA nanoparticles fabricated by β -ME denaturation are promising nanocarriers for hydrophobic substances from chemotherapy drugs to imaging probes.

Guangming Gong, Qinqin Pan, Kaikai Wang, Rongchun Wu, Yong Sun and Ying Lu

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A simple approach to the synthesis of BCN graphene with high capacitance

Boron and nitrogen co-doped graphene (BCN graphene) was prepared through a simple thermal annealing approach in the presence of a single compound, melamine diborate. The as-prepared samples were characterized by scanning electron microscopy, transmission electron microscopy, x-ray photoelectron spectroscopy, Raman spectra and electrochemical techniques. The BCN graphene shows significantly enhanced specific capacitance due to boron and nitrogen co-doping, which permits higher overall doping levels.

Shuo Dou, Xiaobing Huang, Zhaoling Ma, Jianghong Wu and Shuangyin Wang

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Study of carrier concentration in single InP nanowires by luminescence and Hall measurements

The free electron carrier concentrations in single InP core–shell nanowires are determined by micro-photoluminescence, cathodoluminescence (CL) and Hall effect measurements. The results from luminescence measurements were obtained by solving the Fermi–Dirac integral, as well as by analyzing the peak full width at half maximum (FWHM). Furthermore, the platform used for Hall effect measurements, combined with spot mode CL spectroscopy, is used to determine the carrier concentrations at specific positions along single nanowires. The results obtained via luminescence measurements provide an accurate and rapid feedback technique for the epitaxial development of doping incorporation in nanowires. The technique has been employed on several series of samples in which growth parameters, such as V/III-ratio, temperature and dopant flows, were investigated in an optimization procedure. The correlation between the Hall effect and luminescence measurements for extracting the carrier concentra...

David Lindgren, Olof Hultin, Magnus Heurlin, Kristian Storm, Magnus T Borgstr?m, Lars Samuelson and Anders Gustafsson

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Far-IR Spectra and Structures of Small Cationic Ruthenium Clusters: Evidence for Cubic Motifs

The Journal of Physical Chemistry C

DOI: 10.1021/jp510471k

Christian Kerpal, Dan J. Harding, David M. Rayner, Jonathan T. Lyon and André Fielicke

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Size Dependence of Crystal Structure and Magnetic Properties of NiO Nanoparticles in Mesoporous Silica

The Journal of Physical Chemistry C

DOI: 10.1021/jp5112372

Takayuki Tajiri, Seiya Saisho, Masaki Mito, Hiroyuki Deguchi, Kensuke Konishi and Atsushi Kohno

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Development of Lead Iodide Perovskite Solar Cells Using Three-Dimensional Titanium Dioxide Nanowire Architectures

ACS Nano

DOI: 10.1021/nn5058672

Yanhao Yu, Jianye Li, Dalong Geng, Jialiang Wang, Lushuai Zhang, Trisha L. Andrew, Michael S. Arnold and Xudong Wang

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Composition-Dependent Light-Induced Dipole Moment Change in Organometal Halide Perovskites

The Journal of Physical Chemistry C

DOI: 10.1021/jp511314a

Xiaojing Wu, Hui Yu, Linkai Li, Feng Wang, Haihua Xu and Ni Zhao

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Mechanistic Studies of Effect of Dispersity on the Photovoltaic Performance of PTB7 Polymer Solar Cells

Chemistry of Materials

DOI: 10.1021/cm5042953

Luyao Lu, Tianyue Zheng, Tao Xu, Donglin Zhao and Luping Yu

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Upconversion Luminescence of Rare-Earth-Doped Y2O3 Nanoparticle with Metal Nano-Cap

The Journal of Physical Chemistry C

DOI: 10.1021/jp508443g

Kaoru Yamamoto, Minoru Fujii, Shunji Sowa, Kenji Imakita and Kanna Aoki

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Correction to “Growth of 2D ZnO Nanowall for Energy Harvesting Application”

The Journal of Physical Chemistry C

DOI: 10.1021/jp512714s

Balasubramaniam Saravanakumar and Sang-Jae Kim

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Spatially Resolved Photoexcited Charge-Carrier Dynamics in Phase-Engineered Monolayer MoS2

ACS Nano

DOI: 10.1021/nn506469v

Hisato Yamaguchi, Jean-Christophe Blancon, Rajesh Kappera, Sidong Lei, Sina Najmaei, Benjamin D. Mangum, Gautam Gupta, Pulickel M. Ajayan, Jun Lou, Manish Chhowalla, Jared J. Crochet and Aditya D. Mohite

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Is Ice Nucleation from Supercooled Water Insensitive to Surface Roughness?

The Journal of Physical Chemistry C

DOI: 10.1021/jp5113729

James M. Campbell, Fiona C. Meldrum and Hugo K. Christenson

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Enhanced dielectric polarization and electro-responsive characteristic of graphene oxide-wrapped titania microspheres

Electric field-induced particle polarization is essential to the electro-responsive electrorheological (ER) effect of particle suspensions. In this work, we use graphene oxide (GO) as a soft and polar coating shell to prepare GO-wrapped titania dielectric microspheres for use as the dispersal phase of an ER suspension. Under a DC electric field, the ER characteristic of GO-wrapped titania microspheres dispersed in silicone oil is investigated by rheological tests, and then compared with that of a suspension of bare titania microspheres. The results show that the suspension of GO-wrapped titania microspheres possesses an enhanced ER characteristic. Its field-induced shear yield stress and storage modulus are much higher than those of the suspension of bare titania microspheres. The soft and polar GO shell is regarded as the origin of the ER enhancement. Dielectric analysis indicates that wrapping GO can enhance the interfacial polarization and thus improve the ER characteristics o...

Jianbo Yin, Yongjun Shui, Yuezhen Dong and Xiaopeng Zhao

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A measurement technique for circumventing hysteresis and conductance drift in carbon nanotube field-effect transistors

We present a measurement protocol that effectively eliminates both the hysteresis and the temporal drift typically observed in the channel conductance of single-walled carbon nanotube field-effect transistors (SWNT FETs) during the application of gate voltages. Before each resistance measurement, the gate is first stepped through a series of alternating positive and negative voltages to produce a neutral charge distribution within the device. This process is highly effective at removing the hysteresis in the channel conductance, and time-dependent measurements further demonstrate that the drain current is stable and single-valued, independent of the prior measurement history. The effectiveness of this method can be understood within the Preisach hysteresis model, which we demonstrate as a useful framework to predict the observed results.

Andrew Tunnell, Vincent Ballarotto and John Cumings

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Electronic transport in three-terminal triangular carbon nanopatches

The electronic transport properties of three-terminal graphene-based triangular patches are investigated using a combination of semi-empirical tight-binding calculations and Green’s function-based transport theory within Landauer’s framework. The junctions are composed of a triangular structure based on armchair edged graphene nanoribbons. We show how details of the central region influence the resonant electronic transport across the triangular patches and highlight the unique features of the current flow as a function of geometry. These properties indicate an array of functionalities for the development of carbon-based complex nanocircuits and operational devices at the nanoscale.

Ana Luiza Mariano Torres Costa, Vincent Meunier and Eduardo Costa Girão

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Effects of surface activation on the structural and catalytic properties of ruthenium nanoparticles supported on mesoporous silica

Using colloid-based methods to prepare supported catalytic metallic nanoparticles (NPs) often faces the challenge of removing the stabilizer used during synthesis and activating the catalyst without modifying the particles or the support. We explored three surface activation protocols (thermal oxidation at 150 ° C, thermal reduction at 350 ° C, and argon-protected calcination at 650 ° C) to activate ruthenium NPs supported on mesoporous silica (MSU-F), and assessed their effects on the structural and catalytic properties of the catalysts, and their activity by the aqueous phase hydrogenation of pyruvic acid. The NPs were synthesized by polyol reduction using poly- N -vinyl-2-pyrrolidone (PVP) as a stabilizer, and supported on MSU-F by sonication-assisted deposition. The NPs maintained their original morphology on the support during activation. Ar-protected calcination was the most efficient of the three for completely removing PVP from particle surfaces, and provided the hig...

Xianfeng Ma, Rui Lin, Christopher Beuerle, James E Jackson, Sherine O Obare and Robert Y Ofoli

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Bifunctional nanoparticles with magnetism and NIR fluorescence: controlled synthesis from combination of AGET ATRP and ‘click’ reaction

In this work, bifunctional nanoparticles (NPs) capable of emitting near infrared (NIR) fluorescence and generating superparamagnetism under an external magnetic field were prepared by combination of ‘click’ reaction and surface-initiated activators generated by electron transfer for atom transfer radical polymerization (AGET ATRP) of water-soluble poly(ethylene glycol) monomethyl ether methacrylate (PEGMA) and glycidyl methacrylate (GMA) using biocompatible iron as the catalyst on the surface of silica-coated iron oxide (Fe 3 O 4 @SiO 2 ) NPs. The nanosized Fe 3 O 4 @SiO 2 @PPEGMA- co -PGMA@N 3 was prepared through AGET ATRP and alkynyl bearing NIR dye was also prepared; afterwards they were integrated together by ‘click’ reaction. The different stages of surface modification were approved by employing different characterization techniques such as TEM, XRD, XPS, VSM and FT-IR, and the properties of the final NPs...

Weiwei He, Liang Cheng, Lifen Zhang, Xiaowu Jiang, Zhuang Liu, Zhenping Cheng and Xiulin Zhu

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Hitching a ride with motor proteins

Nature Nanotechnology 9, 1 (2014). doi:10.1038/nnano.2013.308

The biological machines that operate in cells are frequently a starting point for the development of synthetic molecular motors.

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The emergence of the nanobiotechnology industry

Nature Nanotechnology 9, 2 (2014). doi:10.1038/nnano.2013.288

Authors: Elicia Maine, V. J. Thomas, Martin Bliemel, Armstrong Murira & James Utterback

The confluence of nanotechnology and biotechnology provides significant commercial opportunities. By identifying, classifying and tracking firms with capabilities in both biotechnology and nanotechnology over time, we analyse the emergence and evolution of the global nanobiotechnology industry.

Elicia Maine

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