Application as Sensor

Thioureas-binding site can be introduced to molecules like anthraquinone and is for use in various kinds of anion or fluoride sensors. Thiourea-based sensor are generally designed to recognize anion through an intermolecular hydrogen bonding.167 171 

---

Low-temperature thermometers are obtained by cutting a metallized wafer of NTD Ge into chips of small size (typically few mm3) and bonding the electrical contacts onto the metallized sides of the chip. These chips are seldom used as calibrated thermometers for temperatures below 30 mK, but find precious application as sensors for low-temperature bolometers [42,56], When the chips are used as thermometers, i.e. in quasi-steady applications, their heat capacity does not represent a problem. In dynamic applications and at very low temperatures T < 30 mK, the chip heat capacity, together with the carrier-to-phonon thermal conductance gc d, (Section 15.2.1.3), determines the rise time of the pulses of the bolometer. 

For applications as electro- or photo-catalysts, or for other applications as sensors, solar cells, electrodes in biosensing and biofuel cells, etc. the problem of the amount of titania is less critical, but there is still the need to optimize the film thickness. One of the active directions of research in this area, in fact, is to maintain the nanostructure, but increase the film thickness. A new benchmark for Ti02 nanotube arrays was recently reached. 

Glasses and ceramics can bond to living tissues if there is bioactive layer. The development of a bioactive hydroxyapatite layer in vivo at body temperature is therefore an important problem.89 Materials with the highest level of bioactivity develop a silica layer that enhances the formation of such a layer. Such sol-gel processes are used to produce bioactive coatings, powders and substrates which allow molecular control over the incorporation and behavior of proteins and cells with applications as sensors and implants. Sol-gel encapsulation of biomolecules within silica matrices has encompassed... 

A special case of nanocrystal that is comprised of a semiconductor is known as a quantum dot Typically, the dimensions of these nanostructures lie in the range 1-30 nm, based on its composition (see below). Quantum dots currently find applications as sensors, lasers, and LEDs. In fact, new high-density disks (e.g., HD-DVD and Blu-ray high-definition DVD formats) may only be read via blue lasers, which... 

Conductive polymers have been investigated for applications as sensors, with sensing accomplished through the following modes ... 

Rodriguez-Mendez M. L., Langmuir-Blodgett films of rare-earth lanthanide bisphthalo-cyanines. Applications as sensors of gases and volatile organic compounds. Comments. Inorg. Chem., 22, 227-239, 2000. 

In the future POLYFETs may have some applications as sensors, switching elements in displays etc. However, nearly all FET applications are limited... 

The strong environment dependence of the photophysical properties of platinum complexes allows their application as sensors. A phosphorescent Pt-Pt complex, shown in Fig. 12, can undergo a photoinduced Pt-Pt distance shortening. This leads to the formation of two distinct excited states and dual emission in the steady state. This photoinduced molecular structure change has a strong dependence on the molecule s... 

Control of the permeability of LPFs will play a crucial role in their possible application as sensor materials or protective coatings. The earlier-mentioned experiments show that it is possible to prepare LPFs with a variety of permeabilities. Constituent polyelectrolytes, deposition conditions, and postdeposition treatments can all be chosen to tailor a film for specific needs. 

In addition to testing to breaking point, a specific test was undertaken on the sensor-containing composite by varying the strain applied on the composite in steps. The results from this test are shown in Fig. 16.20. A change in resistance is noted to follow closely the applied strain. Because the sensors reacts to very small displacements placed upon the composite structure, this indicates its validity for application as sensors for the monitoring of composite parts structural health. 

In this section, interesting synthetic strategies for the construction of boron-based macrocycles and dendrimers [7] are described, as appealing building blocks for applications as sensors [8], catalysts, nanoarchitectures [9], separation, and delivery [10]. 

---