Potentiometric solid-state

Table 6.7 Potentiometric solid-state gas sensors (adapted from Fouletier, 1982)... 

Nafe, H. (2005) Potentiometric solid-state CO2 sensor and the role of electronic conductivity of the electrolyte. Sens. Actuators B, 105 (2), 119-23. 

Yamazoe N, Hisamoto J, Miura N, Kuwata S (1987) Potentiometric solid-state oxygen sensor using lanthanum fluoride operative at room temperature. Sens Actuators 12 415-423... 

The following set of suggested experiments describes the preparation of solid-state and liquid ion-exchange ion-selective electrodes, as well as potentiometric biosensors. 

M. Vazquez, J. Bobacka, M. Luostarinen, K. Rissanen, A. Lewenstam, and A. Ivaska, Potentiometric sensors based on poly(3,4-ethylenedioxythiophene) (PEDOT) doped with sulfonated calix[4]arene and calix[4]resorcarenes. J. Solid State Electrochem. 9, 312-319 (2005). 

Poor adhesion of membrane to metal is the leading cause of failure in solid-state potentiometric sensors [116], For glass membranes, the mismatch of thermal coefficients of expansion between thin glass membrane and metal (mostly Pt) has been attributed to premature failure due to hairline crack formations in the glass layer [60], For polymer-based membranes, water vapor penetration was reported to compromise the membrane-metal interface, therefore affecting the sensor s performance. 

Another problem that is common for all membrane-based solid-state sensors is the ill-defined membrane-metal interface. A large exchange current density is required to produce a reversible interface for a stable potentiometric sensor response. One approach to improving this interface is to use conducting polymers. Conducting polymers are electroactive n-conjugated polymers with mixed ionic and electronic conductivity. They... 

Metal/metal oxides are the materials of choice for construction of all-solid-state pH microelectrodes. A further understanding of pH sensing mechanisms for metal/metal oxide electrodes will have a significant impact on sensor development. This will help in understanding which factors control Nemstian responses and how to reduce interference of the potentiometric detection of pH by redox reactions at the metal-metal oxide interface. While glass pH electrodes will remain as a gold standard for many applications, all-solid-state pH sensors, especially those that are metal/metal oxide-based microelectrodes, will continue to make potentiometric in-vivo pH determination an attractive analytical method in the future. 

W. Vonau, J. Gabel, and H. Jahn, Potentiometric all solid-state pH glass sensors. Electrochim. Acta 50, 4981-4987 (2005). 

J.E. Zachara, R. Toczylowska, R. Pokrop, M. Zagorska, A. Dybko, and W. Wroblewski, Miniaturised all-solid-state potentiometric ion sensors based on PVC-membranes containing conducting polymers. Sens. Actuators B. 101, 207-212 (2004). 

The ion [MoW5Oi9]2 has been isolated in the solid state as a tet-rabutyl ammonium salt (183). The formation of [Mo3W3Oi9]2 in an aqueous solution was proposed on the basis of potentiometric data (184). 

Field effect transistors are miniature, solid-state, potentiometric transducers (Figure 4.22) which can be readily mass produced. This makes them ideal for use as components in inexpensive, disposable biosensors and various types are being developed. The function of these semiconductor devices is based on the fact that when an ion is absorbed at the surface of the gate insulator (oxide) a corresponding charge will add at the semiconductor... 

Lvova, L., Legin, A., Vlasov, Y., Cha, G. S., and Nam, H. (2003). Multicomponent analysis of Korean green tea by means of disposable all-solid-state potentiometric electronic tongue microsystem. Sens. Actuators B 95(1-3), 391-399. 

Potentiometric Sensors Inthe field of ion-selective electrodes, considerable progress has been achieved in the last few years. By buffering the primary ions concentration on a low level in the internal solution, ionic fluxes in the membrane are affected [424-426]. Thus, primary ion leakage into sample solution is hindered, resulting in a tremendous shift of detection limits to lower values for Pb +-selective electrodes, the detection limit up to 10 M level has been achieved for internal solution electrodes [424, 427] and below 10 M for all-solid-state electrodes with conducting polymer solid... 

J. Bobacka. T. Lindfors, A. Lewenstam. and A. Ivaska, All-Solid-State Ion Sensors Using Conducting Polymers as Ion-to-Electron Transducers, Am. Lab., February 2004, 13 A. Konopka, T. Sokalski, A. Michalska, A. Lewenstam, and M. Maj-Zurawska, Factors Affecting the Potentiometric Response of All-Solid-State Solvent Polymeric Membrane Calcium-Selective Electrode for Low-Level Measurement, Anal. Chem. 2004, 76, 6410 M. Fouskaki and... 

The interaction of 2-pyridinecarbaldehyde with Cu(II) has been studied by potentiometric and spectrophotometric methods,522 and formation constants have been determined. The neutral deprotonated complex (167) was characterized in the solid state. 

It is typically on the order of several hundred nanometers. In practice the minimum thickness for polymeric membranes is 50gm or greater, which is far more than one would expect from (6.53). This is apparendy due to the fact that these membranes hydrate in the bulk, thus increasing the dielectric constant. They also form a hydrated layer at the solution/membrane interface (Li et al 1996) which affects their overall electrochemical properties and selectivities. Macroscopic ISEs use relatively thick membranes ( 500jU.m). In contrast, it is desirable to use thin membranes in the construction of asymmetric solid-state potentiometric ion sensors, in order to make their preparation compatible with the thin-layer preparation techniques. 

A potentiometric electrochemical cell consisting of a reference electrode, solid-state electrolyte(s), and an indicator electrode can provide information about the partial pressure of gas in the same way as the cells utilizing ion-selective electrodes and liquid electrolytes can. The general mechanism is as follows. A sample gas, which is part of a redox couple, permeates into the solid-state structure usually through the porous metal electrode and sets up a reversible potential difference at that interface according to the reaction... 

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