Sensors nanocomposite-type

The resistance of the nanocomposite film was also greater than that of the pure tin oxide film, most likely because the presence of the CNTs had led to the introduction of pores. Nonetheless, this illustrates the potential of these nanocomposite-type materials - where both phases are nanocrystalline - in the field of gas sensors. 

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. 

A sensitive and selective electrochemical analysis of the OPs methyl parathion (MPT) and 4-nitrophenol (PNP) has been carried out using a new type p-NiTSPc/p-PPD coated carbon fibre microelectrode (CFME)," and tricresyl phosphate has been determined in aqueous samples and air using a copper nanoparticles and carbon nanotubes-based electrochemical sensor. Similarly, dimethyl methylphosphonate (DMMP) and ethanol vapours have been determined using a high-performance nanocomposite material based on functionalized carbon nanotubes and polymers coated on a surface acoustic wave (SAW) device. ... 

Recently, the production of nanofibres using nanocomposites has attracted attention. This is due to the fact that this type of nanofibre combines the unique properties of nanocomposites with the outstanding characteristics of nanofibres. Metal/polymer nanocomposites have not only the potential to meet the requirements of applications such as photonic and electric sensors, filters, and artificial tissue, but also can act as catalysts. Silver nanoparticles are the most common embedded metal nanoparticles used in conjunction with polymers. This is because silver nanoparticles exhibit remarkable properties including catalytic activity, surface-enhanced Raman scattering activity, high electrical conductivity and antimicrobial activity. 

Polymer matrix nanocomposite is the most important type of nanocomposite in which the performance of a polymer matrix can be enhanced by appropriately adding nanoparticulates to it [12] and good dispersion of the filler can be achieved [ 12]. A imiform dispersion of nanoparticles leads to a very large matrix/filler interfacial area, which changes the molecular mobility, the relaxation behavior and the consequent thermal and mechanical properties of the material. A polymer matrix could be reinforced by much stiffer nanoparticles [13,14] of ceramics, clays, or carbon nanotubes, etc. Recent research on thin films (thickness < 50 micrometer) made of polymer nanocomposites has resulted in a new and scalable synthesis technique increasing the facile incorporation of greater nanomaterial quantities [15]. Such advances will enable the future development of multifunctional small scale devices (i.e., sensors, actuators, medical equipment), which rely on polymer nanocomposites. 

Electrical conduction is also very important for many devices that exploit the huge area of surface or interface per unit volume in zero-dimensional nanostructured materials such as nanoporous materials, granular materials, nanocomposites, and nanoparticle assemblies. Examples of such devices are chemiresistor-type sensors, solar cells, light-emitting diodes, and energy-storage cells. From the point of view of electron... 

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