Biosensors nanoparticles

Here, 1 examine the coupling of particle plasmons excited in nanoparticles with LSPs in surface relief nanostructures. As a biosensor, nanoparticles may serve as linker molecules that amplify the index change due to ligand bindings with... 

MEMS Biosensors Based on Nanoparticles Nanoparticles are often utilized as an analyte recognition element in MEMS biosensors. Nanoparticles have a quite large sensing area mainly due to their extremely small size. This enhances the reaction possibility of biomolecules. Furthermore, sensitivity of the biosensor can be increased when metal nanoparticles are positioned between two metal electrodes. When the analyte conjugated with metal nanoparticle is captured between two electrodes, the electric field intensity is amplified. Gold, silver, metal oxide and magnetic nanoparticles are widely used for detection... 

The current widespread interest in size-dependent optical properties of nanomaterials is a consequence of their many applications in research areas such as chemosensors, biosensors,nanoparticle optics, and surface-enhanced spectroscopy. Recently, interest in surface-enhanced Raman spectroscopy (SERS)... 

Particularly attractive for numerous bioanalytical applications are colloidal metal (e.g., gold) and semiconductor quantum dot nanoparticles. The conductivity and catalytic properties of such systems have been employed for developing electrochemical gas sensors, electrochemical sensors based on molecular- or polymer-functionalized nanoparticle sensing interfaces, and for the construction of different biosensors including enzyme-based electrodes, immunosensors, and DNA sensors. Advances in the application of molecular and biomolecular functionalized metal, semiconductor, and magnetic particles for electroanalytical and bio-electroanalytical applications have been reviewed by Katz et al. [142]. 

Curii ML, Agostiano A, Leo G, Mallardi A, Cosma P, Monica MD (2002) Development of a novel enzyme/semiconductor nanoparticles system for biosensor apphcation. Mater Sci Eng C 22 449-452... 

A large number of possible applications of arrays of nanoparticles on solid surfaces is reviewed in Refs. [23,24]. They include, for example, development of new (elect-ro)catalytical systems for applications as chemical sensors, biosensors or (bio)fuel cells, preparation of optical biosensors exploiting localized plasmonic effect or surface enhanced Raman scattering, development of single electron devices and electroluminescent structures and many other applications. 

In 1994, thiols were firstly used as stabilizers of gold nanoparticles [6a]. Thiols form monolayer on gold surface [18] and highly stable nanoparticles could be obtained. Purification of nanoparticles can be carried out, which makes chemical method of metal nanoparticles a real process for nanomaterial preparation. Various thiol derivatives have been used to functionalize metal nanoparticles [6b, 19]. Cationic and anionic thiol compounds were used to obtain hydrosols of metal nanoparticles. Quaternary ammonium-thiol compounds make the nanoparticle surface highly positively charged [20]. In such cases, cationic nanoparticles were densely adsorbed onto oppositely charged surfaces. DNA or other biomolecule-attached gold nanoparticles have been proposed for biosensors [21]. 

Zhong X, Yuan R, Chai Y, Liu Y, Dai J, Tang D (2005) Glucose biosensor based on self-assembled gold nanoparticles and double-layer 2d-network (3-mercaptopropyl)-trimethoxy-silane polymer onto gold substrate. Sensor Actuator B 104 191-198... 

Zhao W, Chiuman W, Lam JCF, McManus SA, Chen W, Cui Y, Pelton R, Brook MA, Li Y (2008) DNA aptamer folding on gold nanoparticles from colloid chemistry to biosensors. J Am Chem Soc 130(11) 3610-3618... 

To fulfill both the requirement of CFME for the practical applications and the necessity of Au substrate to assemble so-called promoters to construct the third-generation biosensor, Tian el al. have combined the electrochemical deposition of Au nanoparticles (Au-NPs) onto carbon fiber microelectrodes with the self-assembly of a monolayer on these Au-NPs to facilitate the direct electron transfer of SOD at the carbon fiber microelectrode. The strategy enabled a third-generation amperometric 02 biosensor to be readily fabricated on the carbon fiber microelectrode. This CFME-based biosensor is envisaged to have great potential for (he detection of 02" in biological systems [158],... 

X.D. Su, S.F.Y. Li, and J. O Shea, Au nanoparticle- and silver-enhancement reaction-amplified micro-gravimetric biosensor. Chem. Commun. 8, 755-756 (2001). 

The applications of nanoparticles in biosensors can be classified into two categories according to their functions (1) nanoparticle-modified transducers for bioanalytical applications and (2) biomolecule-nanoparticle conjugates as labels for biosensing and bioassays. We intend to review some of the major advances and milestones in biosensor development based upon nanoparticle labels and their roles in biosensors and bioassays for nucleic acids and proteins. Moreover, we focus on some of the key fundamental properties of certain nanoparticles that make them ideal for different biosensing applications. 

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