Biosensors metallic nanoparticles

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]. 

Gutes, A., C. Carraro, and R. Maboudian, Single-layer CVD-grown graphene decorated with metal nanoparticles as a promising biosensing platform. Biosensors and Bioelectronics,... 

Van Duyne RP, Haes AJ, Zou S, Schatz GC (2004) A Nanoscale Optical Biosensor The Long Range Distance Dependence of the Localized Surface Plasmon Resonance of Noble Metal Nanoparticles. J Phys Chem B 108 109-116... 

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... 

Electrospray has been used for many different applications, such as the deposition of paints and coatings on metal surfaces and the deposition of metal nanoparticles and biomolecules on biosensor surfaces, and in a miniaturized version also as a propulsion mechanism in microsatellites (see also the section on electric wind). One particularly interesting application is in fuel atomization, that is, a finer fuel aerosol and atomization will give a higher combustion efficiency and less pollutant emission, which is caused by the effect that finer droplets increase the total surface area on which combustion can start (Lehr and Hiller, 1993). 

These electromagnetic waves are very sensitive to any change in the boundary—for example, to the adsorption of molecules onto the metal surface. SPR has measured the absorption of material onto planar metal surfaces (typically Au, Ag, Cu, Ti, or Cr) or onto metal nanoparticles and is used in many color-based biosensor applications and lab-on-a-chip sensors. To observe SPR, the complex dielectric constants e1 of the metal and s2 of the dielectric (glass or air) must satisfy the conditions Re(ei) < 0 and > e21,... 

Haes, A.J. Zou, S. Schatz, G..C. Van Duyne, R.P. (2004) Nanoscale optical biosensor Short range distance dependence of the localized surface plasmon resonance of noble metal nanoparticles. Journal of Physical Chemistry B 108 6961-6968. 

Njagi, J. Warner, J. Andreescu, S., A bioanalytical chemistry experiment for undergraduate students Biosensors based on metal nanoparticles, J Chent. Educ. 2007, 84. 1180-1182... 

There is an enormous variety of nanomaterials that can potentially be employed in biosensor architectures. The most prominent among them are metal nanoparticles [304], quantum dots [308], and carbon nanotubes [309-311]. AH of them have been employed in biosensors though not necessarily exclusively electrochemical biosensors. Quantum dots (QDs) offer unique absorption properties making them highly suitable for the construction of biosensors with optical readout. The most diverse electrochemical nanobiosensors are, however, obtained from carbon nanotubes (CNTs) which offer a wide range of different apphcations. 

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