Sensors transistor based

Nilsson, D. et al.. An all-organic sensor-transistor based on a novel electrochemical transducer concept printed electrochemical sensors on paper. Sens. Actuators B, 86, 193, 2002. 

D.S. Kim, H.J. Park, H.M. Jung, J.K. Shin, Y.T. Jeong, P. Choi, J.H. Lee, and G. Lim, Field-effect transistor-based biomolecular sensor employing a Pt reference electrode for the detection of deoxyribonucleic acid sequence. Jpn, J. Appl. Phys. 43, 3855-3859 (2004). 

There are three major classes of palladium-based hydrogen sensors [4], The most popular class of palladium-based sensors is based on palladium resistors. A thin film of palladium deposited between two metal contacts shows a change in conductivity on exposure to hydrogen due to the phase transition in palladium. The palladium field-effect transistors (FETs) or capacitors constitute the second class, wherein the sensor architecture is in a transistor mode or capacitor configuration. The third class of palladium sensors includes optical sensors consisting of a layer of palladium coated on an optically active material that transforms the hydrogen concentration to an optical signal. 

In this chapter, we intend to revise the most recent contributions to the aforementioned aspects of Pc research. We will describe how the versatile chemistry of Pcs makes possible the preparation of monofunctionalized macrocycles, mainly aimed at preparing multicomponent systems through reaction with other electroactive moieties. The controlled organization of Pcs in solution and the incorporation of these chromophores into macromolecular structures, as well as the preparation of mono-, bi-, and three-dimensional nanostructures, will be the object of study. Finally, some examples of Pc-based devices (solar cells, sensors, transistors, etc.) will also be given as an example of the real applicability of these molecules. 

CNTs and other nano-sized carbon structures are promising materials for bioapplications, which was predicted even previous to their discovery. These nanoparticles have been applied in bioimaging and drag delivery, as implant materials and scaffolds for tissue growth, to modulate neuronal development and for lipid bilayer membranes. Considerable research has been done in the field of biosensors. Novel optical properties of CNTs have made them potential quantum dot sensors, as well as light emitters. Electrical conductance of CNTs has been exploited for field transistor based biosensors. CNTs and other nano-sized carbon structures are considered third generation amperometric biosensors, where direct electron transfer between the enzyme active center and the transducer takes place. Nanoparticle functionalization is required to achieve their full potential in many fields, including bio-applications. 

A transistor-based chemical sensor used in aqueous environment must be electrically insulated. An ordinary FET sensor produced with a silicon wafer as starting material has four bare lateral edges, which are made when scribing a processed silicon wafer into FET chips. It has bonding pads on its surface for wires that are connected for the electrical operation of a FET (see Fig. la). It is necessary to insulate the bare lateral sides and bonding pad region, and this is usually done by polymer encapsulation. Because a FET chip is very small and the areas to be insulated are closely located to its ion-sensitive gates, which must... 

Electroehemical transdueers are elassified as amperometric, potentiometric or conductometrie [8]. In addition we will here consider field-effect transistor-based transducers separately. Potentiometric sensors make use of the development of an electrical potential at the surface of an electrode when it is placed in a solution containing ions that can exchange with the surface. The potential of the electrode is... 

Widespread interest has arisen in the potential of LB films as biosensors because many believe that the incorporation of biological molecules such as enzymes will lead to novel devices. Some are exploring the deposition of biologically active molecules onto the gate electrodes or oxides of field-effect transistors, but optical sensors, probably based on fiber optics, are the most favored technique. In all cases, the aim is to couple the specificity of inter-... 

Circuitry for setting gradients for piecewise-linear characteristics utilize a three-input OP amplifier to set the gradients for piecewise-linear characteristic of the twilight sensor output. Since the three inputs are at the lowest transistor base potential, the sensor s characteristics are as shown in Fig. 7.13.14 when the inputs are VI, V2, and V3. 

Performance Requirements and Mechanistic Analysis of Organic Transistor-Based Phosphonate Gas Sensors... 

Electrochemical, such as ion-selective electrodes (ISE), ion-selective field affects transistors (ISEET), solid electrolyte gas sensors, semiconductor-based gas sensors, and conducting polymer sensors. Most electrochemical sensors are based on potentiometry, voltammetry, or amperometry although coulometry and conductimetry have also been utilized. 

In this section, the performances of electrical gas sensors based on SWCNTs are reviewed. Three types of gas sensors are introduced field-effect transistor based on individual SWCNT and chemiresistor or field-effect transistor based on SWCNT network. 

Peng, N., Zhang, Q., Lee, Y. C.,Tan, O. K. and Marzari,N. (2008), Gate modulation in carbon nanotube field effect transistors-based NH3 gas sensors . Sensors And Actuators B, 132,191-5. 

Roberts, M. E., LeMieux, M. C. and Bao, Z. (2009), Sorted and aligned single-walled carbon nanotube networks for transistor-based aqueous chemical sensors , ACS Nano, 3,3287-93. 

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