HYBRID SEMICONDUCTING QUANTUM DOTS–METALLIC NANOPARTICLES ARRAYS FOR POSSIBLE NANOPHOTONIC DEVICES

2011 ◽  
Vol 10 (04n05) ◽  
pp. 1113-1118
Author(s):  
M. HARIDAS ◽  
J. K. BASU

Arrays of quantum dots and hybrid arrays of semiconducting quantum dots and metallic nanoparticles have wide range of potential applications from nanophotonics to quantum information processing. Creating such arrays with well-defined morphology and order over a large area is a challenge. We present a reliable method for constructing such arrays using simple self assembly technique. The reliability of the method is verified using AFM. The emission properties of such system are studied using high resolution imaging techniques and we have given the possible explanation for the observed phenomena.

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
David M. Smith ◽  
Verena Schüller ◽  
Carsten Forthmann ◽  
Robert Schreiber ◽  
Philip Tinnefeld ◽  
...  

Nanometer-sized polyhedral wire-frame objects hold a wide range of potential applications both as structural scaffolds as well as a basis for synthetic nanocontainers. The utilization of DNA as basic building blocks for such structures allows the exploitation of bottom-up self-assembly in order to achieve molecular programmability through the pairing of complementary bases. In this work, we report on a hollow but rigid tetrahedron framework of 75 nm strut length constructed with the DNA origami method. Flexible hinges at each of their four joints provide a means for structural variability of the object. Through the opening of gaps along the struts, four variants can be created as confirmed by both gel electrophoresis and direct imaging techniques. The intrinsic site addressability provided by this technique allows the unique targeted attachment of dye and/or linker molecules at any point on the structure's surface, which we prove through the superresolution fluorescence microscopy technique DNA PAINT.


2008 ◽  
Vol 1087 ◽  
Author(s):  
Marco Palumbo ◽  
Simon J. Henley ◽  
Thierry Lutz ◽  
Vlad Stolojan ◽  
David Cox ◽  
...  

AbstractRecent results in the use of Zinc Oxide (ZnO) nano/submicron crystals in fields as diverse as sensors, UV lasers, solar cells, piezoelectric nanogenerators and light emitting devices have reinvigorated the interest of the scientific community in this material. To fully exploit the wide range of properties offered by ZnO, a good understanding of the crystal growth mechanism and related defects chemistry is necessary. However, a full picture of the interrelation between defects, processing and properties has not yet been completed, especially for the ZnO nanostructures that are now being synthesized. Furthermore, achieving good control in the shape of the crystal is also a very desirable feature based on the strong correlation there is between shape and properties in nanoscale materials. In this paper, the synthesis of ZnO nanostructures via two alternative aqueous solution methods - sonochemical and hydrothermal - will be presented, together with the influence that the addition of citric anions or variations in the concentration of the initial reactants have on the ZnO crystals shape. Foreseen applications might be in the field of sensors, transparent conductors and large area electronics possibly via ink-jet printing techniques or self-assembly methods.


2021 ◽  
Vol 9 ◽  
Author(s):  
Gurpal Singh ◽  
Harinder Kaur ◽  
Akanksha Sharma ◽  
Joga Singh ◽  
Hema Kumari Alajangi ◽  
...  

Detection of cancer at an early stage is one of the principal factors associated with successful treatment outcome. However, current diagnostic methods are not capable of making sensitive and robust cancer diagnosis. Nanotechnology based products exhibit unique physical, optical and electrical properties that can be useful in diagnosis. These nanotech-enabled diagnostic representatives have proved to be generally more capable and consistent; as they selectively accumulated in the tumor site due to their miniscule size. This article rotates around the conventional imaging techniques, the use of carbon based nanodots viz Carbon Quantum Dots (CQDs), Graphene Quantum Dots (GQDs), Nanodiamonds, Fullerene, and Carbon Nanotubes that have been synthesized in recent years, along with the discovery of a wide range of biomarkers to identify cancer at early stage. Early detection of cancer using nanoconstructs is anticipated to be a distinct reality in the coming years.


Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 63 ◽  
Author(s):  
Jong Dae Jang ◽  
Changwoo Do ◽  
Joona Bang ◽  
Young Soo Han ◽  
Tae-Hwan Kim

A self-assembled unilamellar vesicle, which can be used as a drug delivery system, was easily and simply fabricated using a blended system of Pluronic block copolymers. Controlling the hydrophilic mass fraction of block copolymers (by blending the block copolymer with a different hydrophilic mass fraction) and temperature (i.e., the hydrophobic interaction is controlled), a vesicular structure was formed. Small angle neutron scattering measurements showed that the vesicular structure had diameters of empty cores from 13.6 nm to 79.6 nm, and thicknesses of the bilayers from 2.2 nm to 8.7 nm when the hydrophobic interaction was changed. Therefore, considering that the temperature of the vesicle formation is controllable by the concentration of the blended block copolymers, it is possible for them to be applied in a wide range of potential applications, for example, as nanoreactors and nanovehicles.


NANO ◽  
2012 ◽  
Vol 07 (01) ◽  
pp. 1250001 ◽  
Author(s):  
XIAOYING QI ◽  
XIAO HUANG ◽  
HAI LI ◽  
YUSONG WANG ◽  
YUN XIA ◽  
...  

Recombinant vault nanoparticles are used as stable nanoscale platforms for controlled self-assembly of various kinds of nanoparticles into the predefined multidimensional architectures. High-yield and uniform discoidal assemblies templated by vaults are constructed from gold nanospheres and quantum dots, while dimeric assemblies are formed from relatively-large gold nanocubes. The vault-templated approach appears to be mainly mediated by the surface and dimensional properties of nanoparticles while less affected by the chemical composition of nanoparticles, making it a universal strategy for fabrication of nanoassemblies with designed properties for potential applications.


Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 133 ◽  
Author(s):  
Adrian Domiński ◽  
Tomasz Konieczny ◽  
Piotr Kurcok

Supramolecular hydrogels that are based on inclusion complexes between α-cyclodextrin and (co)polymers have gained significant attention over the last decade. They are formed via dynamic noncovalent bonds, such as host–guest interactions and hydrogen bonds, between various building blocks. In contrast to typical chemical crosslinking (covalent linkages), supramolecular crosslinking is a type of physical interaction that is characterized by great flexibility and it can be used with ease to create a variety of “smart” hydrogels. Supramolecular hydrogels based on the self-assembly of polypseudorotaxanes formed by a polymer chain “guest” and α-cyclodextrin “host” are promising materials for a wide range of applications. α-cyclodextrin-based polypseudorotaxane hydrogels are an attractive platform for engineering novel functional materials due to their excellent biocompatibility, thixotropic nature, and reversible and stimuli-responsiveness properties. The aim of this review is to provide an overview of the current progress in the chemistry and methods of designing and creating α-cyclodextrin-based supramolecular polypseudorotaxane hydrogels. In the described systems, the guests are (co)polymer chains with various architectures or polymeric nanoparticles. The potential applications of such supramolecular hydrogels are also described.


2010 ◽  
Vol 1273 ◽  
Author(s):  
Hans D. Robinson ◽  
Kai Chen ◽  
Stefan V. Stoianov

AbstractWe present a variation of a standard convective self-assembly technique, where the drying meniscus is restricted by a straight-edge located approximately 100 μm above the substrate adjacent to the drying zone. We find this technique to yield films at roughly twice the growth rate compared to the standard technique. We attribute this to differing local evaporation rates in the two cases. We also investigate how the crystal growth rate depends on ambient relative humidity and find a clear linear dependency, which we attribute to the length of the drying zone being constant over a wide range of humidities.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Victor K. Pustovalov ◽  
Liudmila G. Astafyeva

Different metal homogeneous nanoparticles have been extensively studied in recent years due to their wide range of potential applications. It is very interesting to investigate core-shell nanoparticles with oxide shell from core metal. The formation of oxide shell on metallic nanoparticles can be achieved by different chemical and physical methods including also natural oxidation of pure metallic nanoparticles in gaseous or liquid media, containing oxygen components (air, water, etc.). We numerically calculated efficiency factors of absorptionKabs, scatteringKsca, and extinctionKextof radiation with wavelengthλin the spectral interval 150–1000 nm by spherical homogeneous metallic and two-layered (metal core – oxide metal shell) nanoparticles: Al, Al-Al2O3and Zn, Zn-ZnO with core radii in the range 5–50 nm and shell thickness 5 nm. Analysis of presented results has been carried out.


2000 ◽  
Vol 642 ◽  
Author(s):  
Ellen R. Goldman ◽  
Hedi Mattoussi ◽  
Phan T. Tran ◽  
George P. Anderson ◽  
J. Matthew Mauro

ABSTRACTColloidal semiconductor quantum dots (QDs) are luminescent nanoparticles with size- dependent emission spectra spanning a wide range of wavelengths in the visible and near IR. This property, as well as their higher resistance to photo-degradation compared to organic dye labels, makes QDs potentially suitable for certain biomolecule tagging and multiplexing applications. We describe an electrostatic self-assembly approach for conjugating highly luminescent colloidal CdSe-ZnS core-shell QDs with engineered two-domain recombinant proteins to form conjugates for sensing and imaging applications. The design, preparation, and characterization of high quantum yield IgG antibody-binding protein G bioconjugates using luminescence, electrophoretic gel shift, and affinity assays is reported.


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