Nanoparticles as sensors

Many different applications for gold cysteine nanoclusters have been proposed. One application is the use of citrate capped nanoparticles as sensors for the detection of thiol containing stractures. This application rehes on the fact that thiols can easily displace oxygen coordinated moieties. Zhong et al. have studied this process between cysteine and homocysteine to develop an assay for the homocysteine biomarker, a correlate to cardiovascular disease. When citrate stabilized particles of 13 run were incubated with either thiolate structure, the solution color changed from a dark red to a deep blue. The displacement of citrate by these moieties resulted... 

Apart from the above described core-shell catalysts, it is also possible to coat active phases other than zeolite crystals, like metal nanoparticles, as demonstrated by van der Puil et al. [46]. More examples of applications on the micro level are given in Section 10.5, where microreactors and sensor apphcations are discussed. 

Zheng AF, Chen JL, Wu GN et al (2009) Optimization of a sensitive method for the switch-on determination of mercury(II) in waters using rhodamine B capped gold nanoparticles as a fluorescence sensor. Microchim Acta 164 17-27... 

Toal SJ, Magde D, Trogler WC (2005) Luminescent oligo(tetraphenyl)silole nanoparticles as chemical sensors for aqueous TNT. Chem Commun 43 5465-5467... 

Kouassi, G. K. Irudayaraj, J. Magnetic and Gold-Coated Magnetic Nanoparticles as a DNA Sensor. Anal Chem. 2006, 78, 3234-3241. 

Dendrimers are a special class of arborescent monodisperse nanometer sized molecules that have been used in the synthesis of Au NPs as surface stabilizers or nanoreactor/templates for nanoparticle growth. Moreover, these hybrid nanomaterials have great potential for application in different fields such as sensors, imaging in cells, electrooptical devices, catalysis, drug delivery agents, and so on. 

McFarland, A. D., Van Duyne, R. P., Single silver nanoparticles as real-time optical sensors with zeptomole sensitivity. Nano Letters 2003,3, 1057-1062. 

Chapter 9 Modified Nanoparticles as Nanoelectrocatalysts and Amplifying Sensors... 

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