Quantum dots nanoparticle assembly

Methods for the design of size- and even shape-controlled [186,190,191,370-372] metallic nanoparticles have reached a rather mature stadium thanks to the contributions of the pioneer groups of the last 25 years. Applications in a number of fields of practical Nanotechnology are now moving fast into the focus of R D [203,373]. For an overview on the potential application of metal nanoparticles in the rapidly growing fields of quantum dots, self-assembly, and electrical properties, the reader is advised to consult recently published specialist review articles, e.g.. Refs. [160,281] and book chapters (cf Chapters 2, 4, and 5 in Ref. [60]). In the following three sub-sections the authors restrict themselves to a brief summary of a few subjects of current practical interest in fields with which they are most familiar. 

Fig. 56. TEM images of DNA-linked gold network (a) an assembly of 8 and 30 nm gold particles (b) higher resolution image of (a) (c) control experiment without DNA (d) HR-TEM image of a portion of a hybrid Au/quantum dot (QD) assembly. The lattice fringes of the QDs, which resemble fingerprints, appear near each Au nanoparticle, (e) A satellite structure formed using a 60-fold excess of the 8 nm particles. Reproduced with permission from Ref. (185). Copyright 2000, American Chemical Society.

The mostly used methods to monitor LbL deposition on monodisperse PS-latex particles for various substances are SPLS method and microelectrophoresis. Inorganic (magnetite, silica, titania and fluorescent quantum dots) nanoparticles [32-34], lipids [35-37] and proteins (albumin, immunoglobulin and others) [29, 38, 39] were incorporated as building block for shell formation on colloidal particles. In paper [39] the construction of enzyme multilayer films on colloidal particles for biocatalysis was demonstrated. The enzyme multilayers were assembled on submicrometer-sized polystyrene spheres via the alternate adsorption of poly(ethyleneimine) and glucose oxidase. The high surface area bio-multilayer coated particles formed were subsequently utilized in enzymatic catalysis. The step-wise coating of different lipids alternated with polyelectrolytes was performed by adsorption of preformed vesicles onto... 

For example, two-dimensional iron-oxide nanoparticle array can be prepared using ordered ferritin molecules as the template. Au and CdSe — ZnS quantum dots can assemble into ordered arrays using a chaperonin protein template, which was modified with thiol groups to bind the nanoparticles via metal-ligand interactions. Au nano-... 

Valencia PM, Basto PA, Zhang L, Rhee M, Langer R, Farokhzad OC, Kamik R (2010) Single-step assembly of homogenous lipid-polymeric and lipid-quantum dot nanoparticles enabled by microfluidic rapid mixing. ACS Nano 4(3) 1671-1679... 

Research on semiconductor nanoparticle technology by chemists, materials scientists, and physicists has already led to the fabrication of a number of devices. Initially, Alivisatos and co-workers developed an electroluminescence device from a dispersion of CdSe nanoparticles capped with a conducting polymer349 and then improved on this by replacing the polymer with a layer of CdS, producing a device with efficiency and lifetime increased by factors of 8 and 10, respectively. 0 Chemical synthetic methods for the assembly of nanocrystal composites, consisting of II-VI quantum dot polymer composite materials,351 represent one important step towards the fabrication of new functional devices that incorporate quantum dots. 

Fig. 2 A quantum dot transport structure, consisting of a source, a drain, and a gate, with gold nanoparticles surrounded by DNA (the bright white dots). The transport through these structures can be fitted well to a simple Coulomb blockade limit description. From S.-W. Chung et al. Top-Down Meets Bottom-Up Dip-Pen Nanolithography and DNA-Directed Assembly of Nanoscale Electrical Circuits Small (2005) 1, 64-69. Copyright Wiley-VCH Verlag GmbH Co. KGaA. Reproduced with permission...

Biomimetic Synthesis of Nanoparticles Carbonyl Complexes of the Transition Metals Metallic Materials Deposition Metal-organic Precursors Polynuclear Organometallic Cluster Complexes Porous Inorganic Materials Self-assembled Inorganic Architectures Semiconductor Nanocrystal Quantum Dots Sol-Gel Encapsulation of Metal and Semiconductor Nanocrystals. 

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