Sensor Chemistry

Table 10. Polymers and indicator dyes for covalent immobilization of the sensor chemistry.

Table 17. Sensor chemistry for gaseous and aqueous oxygen.

Figure 10. Combining sensor chemistry with optical transducers.

Hitchman, M. L. and Hill, H. A. O., Electroanalysis and electrochemical sensors . Chemistry in Britain, 22, 1117-1124 (1986), provides a lively, general introduction to this subject, giving details of sensors based on potentiometry, such as ISEs, together with some historical background. 

CMPO, the selective extractant chemistry in TRU-Resin, can be impregnated into polymers that also contain organic fluor molecules to develop sensor materials, as described previously for crown ether and liquid anion-exchange chemistry. Actinide sensing by this approach has been described.96 135 137 Such sensor chemistries have potential for use in the development of on-line monitors. 

Yoshioka, T, Miznno, N. and Iwamoto, M. (1991), La203-loaded Sn02 Element as a CO2 Gas Sensor , Chemistry Letters, 20,7,1249-52. 

The Inorganic 9. Calcium-doped cerium oxide (Ce02) is unsuitable as a solid electrolyte in a Nemst sensor Chemistry of for measuring the oxygen concentration and in a fuel cell. Why ... 

Optieal Array of rugate Different surface filter sensors chemistries on chip HF, HCl, aliphatic organic substance detection (Ruminski et al. 2011 Shang et al. 2011b Sweetman and Voelcker 2012)... 

The sensing schemes described in this section may also be used for sensing other analytes that cause a change in pH. The preparation of nanosensors also is conceivable by coating single UCNPs with respective sensor chemistry. 

Since the range of what can be done synthetically at surfaces is now developing rsq)idly, it seems likely even more sorts of responsive surfaces will be developed. Such materials should frnd useful roles in areas like adhesion, permeability, biocompatibility, sensor chemistry and corrosion passivation. 

Fig. /. Cross-section through a planar optical sensor membrane composed of an inert solid support, and cm optically responsive sensor chemistry. A light source IS placed underneath the sensor along with a photodetector which measures the intensity of the light emitted by the sensing layer. Sensor membranes of that kind are used in flow cells as shown in Fig. 3.

Conventional glass capillaries with an inner diameter of typically 700 pm, and coated - on the inner wall - with a sensor chemistry, recently have been shown [14] to be excellent "integrated micro-sensors" (Fig 5) In contrast to former capillary type devices [15,16], such capillary sensors have attractive novel features including (a) a minute sample volume (typically 8 fiL), and (b), a sample cavity which also acts as an optical waveguide so they can easily be subjected to optical interrogation Most noteworthy, such capillaries may be used as devices for direct sampling... 

Fig. 6 shows the response to varying concentrations of carbon dioxide. It is obvious that not only the signal change is large, but also the response time is much faster than that of a conventional sensor chemistry deposited in much thicker layer... 

---