Silver nanoparticle deposition from suspension is proposed as a route for the morphological design of controllably disordered self-affine substrates for surfaceenhanced Raman sensing of water pollutants. Ionic strength is used as a variable parameter to control the deposition process and, ultimately, the morphology of deposited substrates. The critical dependence of the enhancement factor on th...

We report the growth of well-oriented nest (reticulum)-like and lotus flower-like submicron structures of ZnO, over gold and silver nanoparticle assemblies, respectively. The structures were grown by a convenient chemical bath deposition method in a nutrient solution made of zinc nitrate (Zn(NO3)2 Æ 6H2O) and methyl amine (CH3NH2) at low temperature. SEM, XRD, Raman, UV–Vis and fluorescence spe...

We propose a model that can account for the experimentally observed phase behavior of DNA-nanoparticle assemblies [J. Am. Chem. Soc. 125, 1643 (2003)]; Science 289, 1757 (2000)]]. The binding of DNA-coated nanoparticles by dissolved DNA linkers can be described by exploiting an analogy with quantum particles obeying fractional statistics. In accordance with experimental findings, we predict tha...

We report on preparing assemblies of gold nanoparticles with continuous gradients in number density on flat silica-covered substrates. The methodology consists of (i) first forming a one-dimensional molecular gradient of amino groups (-NH2) on the substrate by vapor deposition of amine-terminated silane molecules, followed by (ii) attachment of gold nanoparticles to -NH2 functional groups by im...

Small angle X-ray scattering is a primary tool for resolving the crystal structures of self-assembled nanoparticle superlattices [1]. However, it is not quite informative when periodic lattices are broken into clusters due to their inhomogeneity. Therefore, it is desirable to develop a method to rapidly reconstruct the three-dimensional architecture of cluster ensembles in real space. Conventio...

Jeffrey B. Kortright,1 Olav Hellwig,2 Karine Chesnel,1 Shouheng Sun,3 and Eric E. Fullerton2 1Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA 2San Jose Research Center, Hitachi Global Storage Technologies, 650 Harry Road, San Jose, California 95120, USA 3IBM T. J. Watson Research Center, Yorktown Heights, New York 10598, USA (Received 21 October 2004; published 4 January ...

An experimental system has been designed to examine the assembly of nanoparticles in a variety of process engineering applications. These applications include the harvesting from solutions of nanoparticles into green parts, and the subsequent sintering into finished components. The system is based on an x-ray microtomography with a spatial resolution down to 5 mm. The theoretical limitations in...

Nanostructured sensing arrays combined with patternrecognition analysis are expected to provide new opportunities for enhancing the design of sensor materials in terms of sensitivity and selectivity. This paper describes an example in which the sensory properties of the thin film assemblies are exceptionally fine-tunable in terms of nanoparticle size, composition, thickness, and spatial propert...

DNA origami is a novel self-assembly technique allowing one to form various two-dimensional shapes and position matter with nanometer accuracy. We use DNA origami templates to engineer surface-enhanced Raman scattering substrates. Specifically, gold nanoparticles were selectively placed on the corners of rectangular origami and subsequently enlarged via solution-based metal deposition. The resu...

Recently, it has been shown that nanoparticles with a narrow size distribution can self-organize into highly ordered fcc supra-crystals. This new generation of materials have been found to exhibit unique collective properties, which arise from the periodic ordering of the nanoparticles. Using the expertise we have to control the ordering of cobalt nanoparticles in 3D assemblies, we have been ab...