Field chemically sensitive

Janata, J. Chemically Sensitive Field Effect Transistors, in Solid State Chemical Sensors (Janata, J., Huber, R. J., eds.) New York Academic Press 1985, p. 65... 

Shin JE. 1989. Evaluation of chemically-sensitive field-effect transistors for detection of organophosphorus compounds. Wright-Patterson AFB, OH Air Force Institute of Technology. NTIS No. AD-A215-536. 

G.F. Blackburn, Chemically sensitive field-effect transistors, in Biosensors Fundamentals and Applications (A.P.F. Turner, I. Karube, and G.S. Wilson, eds), pp. 481-530. Oxford University Press, Oxford (1987). 

L.J. Bousse, N.F. de Rooij, and P. Bergveld, Operation of chemically sensitive field-effect sensors as a function of the insulator-electrolyte interface. IEEE Trans. Electron Dev. 30, 1263-1270 (1983). 

Wells are purged until stable readings are obtained for field chemical parameters including pH, temperature, dissolved oxygen, redox and electrical conductivity. Samples are then collected for a wide variety of chemical parameters. Time sensitive parameters are analyzed within specific holding times. For example, alkalinity and hydrogen sulphide are measured at the time of sampling, iodide... 

In the case of chemically sensitive devices, the interaction of a given volatile compound or ions in solution can produce one of the following changes mass, charge, temperature, refractive index, magnetic field, work function. For each of these changes suitable transducers are now available. 

Chemically modified waxes, 26 220 Chemically resistant fibers, 13 389 Chemically sensitive field-effect transistors (ChemFETs), 22 269. See also Field effect transistors (FETs)... 

J. Janata and R. J. Huber, Chemically sensitive field effect transistors. Chapter 3 of... 

During these tests, the SeaPup sensor had a third-party verified, in-field TNT sensitivity of 4 ppb. While it is generally believed that a sensitivity of 4 ppb is not adequate for detecting all UUXO, the results of the studies of UUXO in Halifax Harbor [1, 2] suggest that this level of sensitivity will enable detection of some UUXO items. Further improvements in sensitivity of detectors may soon make detection of UUXO possible with chemical sensors, providing an orthogonal detection capability for detection methods such as sonar. 

Although chemical sensitization is a more complex process than immunosuppression, by far most of the efforts on developing in vitro assays are in this field. An important reason for this is that from the various fields of immunotoxicity, most of the animals are used for sensitization testing. In fact the number of animals required for sensitization is second only after developmental toxicity testing. 

The shallow and deep levels play the important role in the sensitization process. Detailed research in this field has shown the presence of four local electron centers in the energetic spectrum of the sensitized PVC in the range 0.6-3.3 eV [63,64]. The density of localized states was of the order 1018 1019 cm-3. These can play essential role in spectral and chemical sensitization due to their influence on photogeneration, recombination and charge transfer processes. 

Figure 3. Ionic leakage paths in chemfet structures a.Schematic illustration of ionic leakage paths around the chemically sensitive membrane. Leakage through the membrane also occurs but is not illustrated b. Schematic illustration of leakage at the surface of a standard ion sensitive field effect transistor.

H. E. Katz, Chemically Sensitive Field-efFect Transistors and Chemiresistors New Materials and Device Structures , Electroanalysis 16, 1837 (2004). 

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