Core Chemical Functions

While the variety of NPs used in catalytic and sensor applications is extensive, this chapter will primarily focus on metallic and semiconductor NPs. The term functional nanoparticle will refer to a nanoparticle that interacts with a complementary molecule and facilitate an electrochemical process, integrating supramolecular and redox function. The chapter will first concentrate on the role of exo-active surfaces and core-based materials within sensor applications. Exo-active surfaces will be evaluated based upon their types of molecular receptors, ability to incorporate multiple chemical functionalities, selectivity toward distinct analytes, versatility as nanoscale receptors, and ability to modify electrodes via nanocomposite assemblies. Core-based materials will focus on electrochemical labeling and tagging methods for biosensor applications, as well as biological processes that generate an electrochemical response at their core. Finally, this chapter will shift its focus toward the catalytic nature of NPs, discussing electrochemical reactions and enhancement in electron transfer. 

The title ligands are the monoanionic 10 (see Section 4.2.5), 26-29 and 54 (see also 79, 80 and 83), the dianionic 30-52 (see also 77) and the trianionic 53 (see also 84). These are chelating ligands, hence firmly bound to the Ln core. Their function has largely been that of supporting ligands. Some of them have had a role not only in /-block but also early d-block metal chemistry certain of the derived compounds have been examined as catalysts for a variety of organic chemical transformations. 

The emission band position is also influenced by the electron-withdrawing and electron-donating effect of the addend, respectively, and by the type of chemical functionalization (e.g., various size of the rings fused to the fullerene core). For example, it has been reported for three different fullerene derivatives that an enhanced electron-withdrawing effect causes an increasing red-shift of the emission band [108], Another example is a C6o derivative 12 (Fig. 10). The emission maxima appears at 705 nm, but if there are methoxy groups additionally attached to the anthryl moiety the emission maxima is shifted to 712 nm [92],... 

Dendrimers are molecules with regularly placed branched repeat units. They are also known as Starburst, Cascade or Arborols. These names describe aspects of their molecular architecture. Dendrimers consist of different parts (see Fig. 1). Each dendrimer has a core or focal point. The core is the central unit of the den-drimer and can formally be regarded as the center of symmetry for the entire molecule. The core has its characteristic branching functionality, i.e. the number of chemical bond by which it is connected to the rest of the molecule (Fig. la). The focal point plays the same role as the core. Moreover,it has a chemical functional group not found elsewhere in the dendrimer. 

Humic substance has a complex structure, comprising a hydrophobic core carrying functional radicals, mainly carboxyls and hydroxyls. Thus, humic substances can react with different products of various chemical functions, and so they interact ecologically with all classes of toxic products such as heavy metals, pesticides, etc. 

Specialty companies have started to respond to these threats in two ways. One is by continuously reducing costs - including reductions in core specialty chemical functions Hke technical services and R D. Many observers feel that these... 

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