Redox Field Effect Transistor

This list can be divided into three main classes based mainly on function and redox state. First, applications that utilize the conjugated polymer in its neutral state are often based around their semi-conducting properties, as in electronic devices such as field effect transistors or as the active materials in electroluminescent devices. Secondly, the conducting forms of the polymers can be used for electron transport, electrostatic charge dissipation, and as EMI-shielding mate-... 

The ion sensitive field-effect transistor (ISFET) is a special member of the family of potentiometric chemical sensors [6,7. Like the other members of this family, it transduces information from the chemical into the electrical domain. Unlike the common potentiometric sensors, however, the principle of operation of the ISFET cannot be listed on the usual table of operation principles of potentiometric sensors. These principles, e.g., the determination of the redox potential at an inert electrode, or of the electrode potential of an electrode immersed in a solution of its own ions (electrode of the first kind), all have in common that a galvanic contact exists between the electrode and the solution, allowing a faradaic current to flow, even when this is only a very small measuring current. 

Yamamoto, T. et al., Ambipolar field-effect transistor (FET) and redox characteristics... 

These transducers include potentiometric electrodes and field effect transistors for H (and indirectly COj or NHj), pH- and 02-sensitive fiber-optic devices, and amperometric electrodes for O2, H2O2, and redox mediators. 

REDOX-SENSITIVE FIELD-EFFECT TRANSISTORS AS TRANSDUCERS FOR MICRO-ANALYSIS SYSTEMS... 

A new type of (bio)chemical sensor, the redox-sensitive field-effect transistor is described It consists of a conventional ISFET with a noble metal added on top of the gate insulator The gate electrode is modified with a redox polymer containing osmium complexes The potentiostatic multi-puls method is introduced which allows the adjustment of the redox potential of the gate to a desired value in a stepwise way It is shown that the open circuit potential after switching off the potentiostat is a good measurement of the presence of the redox active species NADH... 

Aguirre CM, Levesque PL, Paillet M, Lapointe F, St-Antoine BC, Desjardins P, Martel R (2009) The role of the oxygen/water redox couple in suppressing electron conduction in field-effect transistors. Adv Mater 21 3087-3091... 

These devices are based on the measurement of either electrochemical potential or faradaic current associated with redox reactions at an electrode. They are particularly suitable for enzyme-substrate receptor systems by virtue of the ionic products often produced in such reactions. The sensing membranes of the ion-selective electrodes previously described have been combined with semiconductor devices for miniaturization, low-impedance output, signal amplification, and capability of on-chip processing. The ion-sensitive field effect transistor (ISFET) is based on replacement of the conventional transistor gate with the ion-... 

Olhls have also been applied to the detection of redox gases. For example, Lee et al. demonstrated a PANI-based OTFT ammonia sensor and analyzed its performance. Ammonia concentration was obtained from the variation of the drain current of the transistor. In the absence of analyte, the output characteristics (Figure 13(a)) were consistent with operation as a p-channel depletion-mode field-effect transistor. When the OTFT was tested in various ammonia concentrations, the data show that the drain current saturation level was sensitive to ammonia concentration. Figure 13(b) shows the result of interactions of the OTFT with ammonia concentrations from air (0 ppm) up to... 

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