Assembly and Immobilization of Metal Nanoparticles

The science and technology of metal nanoparticles are well established during the past several decades fl om the viewpoints of both fundamental and applied aspects [1-3]. Researches on metal nanoparticles are the subject of one of the most 

Measurement Solution Research Center, National Institute of Advanced Industrial Science and Technology (AIST), 807-1, Shuku-machi, Tosu, Saga 841-0052, Japan e-mail nao-terasaki aist.go.jp 

Division of Materials Science and Engineering, Faculty of Engineering, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Sapporo, Hokkaido 060-8628, Japan e-mail tetsu eng.hokudai.ac.jp 

Ohtsu (ed.), Pmgress in Nanophotonics 1, Nano-Optics and Nanophotonics, DOI 10.1007/978-3-642-17481-0 6, Springer-Verlag Berlin Heidelberg 2011 

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Assembly and Immobilization of Metal Nanoparticles [I] PS sphere as 3D template... 

Enzyme sensors are another important application of metal nanoparticles in CMEs besides nonenzyme sensors. Many enzymes can keep their activity when anchored onto gold nanoparticles. A novel method for fabrication of a biosensor based on the combination of sol-gel and self-assembled techniques has been introduced very recently. For example, the gold nanoparticles and enzyme horseradish peroxidase (HRP) can be successfully immobilized on gold electrode by the help of sol-gel with thiol groups, and the direct electrochemistry of HRP has been achieved and the biosensor thus prepared exhibits fast response, good reproducibility, and long-term stability. 

The nanoparticles prepared in the reverse micellar systems need to be recovered from reverse micelles and immobilized onto stable supports [122, 123]. There have been several reports relating to the immobilization of nanoparticles from reverse micellar systems onto supports made from inorganic and organic materials. For example, dithiol molecules can also be used for the immobilization of metal and semiconductor nanoparticles. Colvin et al. have demonstrated the immobilization of CdS nanoparticles, prepared in the reverse micelles, onto the self-assembled dithiol monolayers on an Au substrate [124]. This approach was used to prepare an Au-CdS nanoparticle multilayer [125] and a CdS nanoparticle multiplayer on Au substrate [126]. Nakanishio et al. demonstrated the layer-by-layer self-assembly of CdS and ZnS nanoparticles on Au substrate, from a reverse micellar solution, using dithiol molecules [127, 128]. In these methods, the preparation of the CdS nanoparticles is completely separated from the immobilization procedure and hence the chemical and physical properties of the nanoparticles can be well controlled when using an appropriate reaction medium such as a reverese micellar system. 

The development of assemblies of inorganic materials with biomolecules has emerged as a novel approach to the controlled fabrication of functionalized nanostructures and networks.5 The practice of DNA sequence detection is especially relevant for forensic sciences, food safety, genetics and other fields.6 The immobilization of single strand DNA probes onto solid materials such as noble metal nanoparticles has proved to be the basis for a multitude of quite different nanobiotech-nological and biomedical applications, including the DNA driven assembly of nanoparticles and biosensors.5-11... 

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