Sensors metallic nanoparticle

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. 

There is no doubt that metallic nanoparticles that have defined sizes and shapes will become key components of a number of novel, highly sophisticated products, the prototypes of which are currently emerging from the industrial R D departments. The outlook is promising for the industrial production of defined 1.4nm metal clusters for use as single electron switches or transistors, for the cost-effective fabrication of ultrapure metallic nanomaterials needed for dye solar cells or sensors, and for the reproducible production of (particularly) efficient and durable... 

Metal nanoparticles have been actively synthesized for applications as catalysts, sensors, adsorbents, analytical probes and optical data storages [1-7]. This is due to the fact that the physicochemical properties of metal nanoparticles can be... 

The polymer resulting from oxidation of 3,5-dimethyl aniline with palladium was also studied by transmission electron microscopy (Mallick et al. 2005). As it turned out, the polymer was formed in nanofibers. During oxidative polymerization, palladium ions were reduced and formed palladium metal. The generated metal was uniformly dispersed between the polymer nanofibers as nanoparticles of 2 mm size. So, Mallick et al. (2005) achieved a polymer- metal intimate composite material. This work should be juxtaposed to an observation by Newman and Blanchard (2006) that reaction between 4-aminophenol and hydrogen tetrachloroaurate leads to polyaniline (bearing hydroxyl groups) and metallic gold as nanoparticles. Such metal nanoparticles can well be of importance in the field of sensors, catalysis, and electronics with improved performance. 

Enzymes functionalized with metallic NPs were used as biocatalytic hybrids for the growth of metallic nanowires. The catalytic enlargement of metal nanoparticles by products generated by different enzymes was used to develop different optical sensors that follow the activities of enzymes and analyze their substrates.57 For example, hydrogen peroxide generated by the biocatalyzed oxidation of glucose by O2 in the... 

Methods to electrically wire redox proteins with electrodes by the reconstitution of apo-proteins on relay-cofactor units were discussed. Similarly, the application of conductive nanoelements, such as metallic nanoparticles or carbon nanotubes, provided an effective means to communicate the redox centers of proteins with electrodes, and to electrically activate their biocatalytic functions. These fundamental paradigms for the electrical contact of redox enzymes with electrodes were used to develop amperometric sensors and biofuel cells as bioelectronic devices. 

Willner and coworkers demonstrated three-dimensional networks of Au, Ag, and mixed composites of Au and Ag nanoparticles assembled on a conductive (indium-doped tin oxide) glass support by stepwise LbL assembly with A,A -bis(2-aminoethyl)-4,4 -bipyridinium as a redox-active cross-linker.8 37 The electrostatic attraction between the amino-bifunctional cross-linker and the citrate-protected metal particles led to the assembly of a multilayered composite nanoparticle network. The surface coverage of the metal nanoparticles and bipyridinium units associated with the Au nanoparticle assembly increased almost linearly upon the formation of the three-dimensional (3D) network. A coulometric analysis indicated an electroactive 3D nanoparticle array, implying that electron transport through the nanoparticles is feasible. A similar multilayered nanoparticle network was later used in a study on a sensor application by using bis-bipyridinium cyclophane as a cross-linker for Au nanoparticles and as a molecular receptor for rr-donor substrates.8... 

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,... 

Nanoparticles consisting of noble metals have recently attracted much attention because such particles exhibit properties differing strongly from the properties of the bulk metal [1,2], Thus, such nanoparticles are interesting for their application as catalysts [3-5], sensors [6, 7], and in electronics. However, the metallic nanoparticles must be stabilized in solution to prevent aggregation. In principle, suitable carrier systems, such as microgels [8-11], dendrimers [12, 13], block copolymer micelles [14], and latex particles [15, 16], may be used as a nanoreactors in which the metal nanoparticles can be immobilized and used for the purpose at hand. 

An LSPR bio-sensor based on particle plasmons uses plasmon excitation in small metal particles that are often sized at a few tens of nanometers. Metallic nanoparticles... 

These fundamental works and discoveries have stimulated an avalanche of investigations on metal nanoparticles in the gas phase, in solution, and on surfaces [43]. In this chapter, the focus will be on nanoparticles on surfaces and, in particular, on gold nanoparticles (AuNPs) on waveguides, both planar strucmres and fibers, as well as photonic crystals with the aim of sensor application. 

Transition metal nanoparticles have attracted great attention due to their unique size-dependent properties and applications in diverse areas, including magnetic storage materials, catalysis, sensors and drug delivery. Depositions of various Pt-containing alloys are summarized in Table 2. Particularly, chemically synthesized transition metal alloy... 

The proposed approach is a universal method that can be applied for successful fabrication of metal-clay nanocomposites with high thermal stability, high dispersity of metal nanoparticles inside the clay matrix and catalytic activity. This work provides original insights into the production of layered naiocomjwsites loaded with inorganic nanoparticles. The ultrasonic treatment accelerates the incorporation process. The Au nanoparticle /clay nanocomposites can be useful for creation of different devices such as nanocondenser systems, sensors, optoelectronic elements. 

Metal Nanoparticles Embedded Polymer Matrix Modified Electrodes for Direct Electrocatalysis and Electrochemical Sensor... 

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