Gold-biomolecule 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]. 

The branched polysaccharide dextran is assembled with alkanethiol-modified gold nanoparticles and the resulting nanocomposite is then functionalized to facilitate the specific binding of target biomolecules. This biorecognition process can be easily detected by particle plasmon resonance (PPR), based on the optical properties of gold nanoparticles [163]. 

Another plasmon resonance approach for detection of mercury vapour is based on localized plasmon resonance in gold nanoparticles deposited on transparent support (Fig. 12.4, right). Changes of the refractive index of gold nanoparticles due to adsorption of mercury should lead to modification of the gold plasmon band of optical adsorption spectra. This approach has been applied successfully for investigation of interaction of biomolecules however, to our knowledge there is still no report on its applications for detection of mercury vapour. 

The use of gold nanoparticles as an electrochemical label for bionanalysis was introduced by Costa-Garcia and coworkers 62 Adsorptive voltammetry was used to detect the gold signal and monitor biotin-stieptavidin interactions on a pretreated carbon paste electrode with an adsorbed biotinylated albumin layer after immersion into a solution of streptavidin-coated colloidal gold. While colloidal gold had found widespread use as a histochemical label for biomolecules and an optical label based on absorption... 

Kim NH, Baek TJ, Park HG, Seong GH (2007) Highly sensitive biomolecule detection on a quartz crystal microbalance using gold nanoparticles as signal amplification probes. Anal... 

The utilization of biomolecules and bio-organisms, such as bacteria, proteins, and polysaccharide, for the synthesis of Ag and gold nanoparticles (Chandran et al., 2006). 

The excitation of the surface plasmon effect also induces strongly enhanced fluorescence properties of gold nanoparticles due to the enhanconent in the radiative rate of the inter-band electronic transitions relative to that in bulk metals. Metal nanoparticles, especially gold nanorods exhibit enhanced two-photon luminescence (TPL) and multi-photon luminescoice (MPL) [7, 8]. Strongly-enhanced TPL has been observed from individual particles [9, 10] and particle solutions [11] under femtosecond NIR laser excitation. This observation raises the possibility of nonlinear optical imaging in the NIR region, where water and biomolecules have... 

Electrocatalytic Activity of Gold Nanoparticles Toward Small Biomolecules... 

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