Field effect transistor sensors

The use of arachidic acid and different amphiphilic calixarenes for modifying of field effect transistor sensors and determination of some volatile organic contaminants will be considered. 

Figure 7. Scheme of a field effect transistor sensor. 

Y. Ishige, M. Shimoda, and M. Kamahori, Immobilization of DNA probes onto gold surface and its application to fully electric detection of DNA hybridization using field-effect transistor sensor. Jpn. J. Appl. Phys. 45, 3776-3783 (2006). 

The idea of exploiting these new conducting polymers for the development of flexible diodes and junction transistors, as well as for selective field effect transistor sensors, has been proposed and experimentally confirmed, and thus we may, perhaps optimistically, look forward to a time when popular electronic devices can be based on low cost, flexible and modular polymer components. 

CNTs can be easily doped by noncovalent means via molecular adsorption, an aspect that has been considerably exploited to develop ultrasensitive field effect transistor sensors [88-91]. However, substitutional doping with B and N to confer p and n character to the CNTs has also been carried out [92]. Such doped systems can be more susceptible to react with donors or acceptors molecules (depending on the doping) allowing the chemically reactivity to increase. 

Figure 7.15a is a schematic illustration of the field-effect transistor sensor with semiconductor 5, 5 -bis (4-n-hexyl-phenyl)-2, 2/-bithiophene (6PTTP6) film serving as the active layer. This unfunctionalized sensor shows some inherent sensitivity to DMMP. Figure 7.16 compares the change of the saturation source-drain current of 6PTTP6 sensor before and after exposure to saturated DMMP vapor, with source-drain voltage Vb set to be —100 V. 

Abstract This chapter focuses on the performances of gas sensors based on single-walled carbon nanotubes (SWCNTs).The chapter first reviews chemiresistor and field-effect transistor sensor architectures. Theoretical models based on doping effect and Schottky barrier modulation are correlated to the percolation of metallic carbon nanotubes. The functionalisation strategies of carbon nanotubes, used to acquire a gas selectivity, are discussed and offer promising application for the monitoring of air quality, or military and medical applications. 

Chen, C.-R, Ganguly, A., Lu, C.-Y. et al. (2011) Ultrasensitive in situ label-free DNA detection using a GaN nanowire-based extended-gate field-effect-transistor sensor. Anal. Chem., 83 (6), 1938-1943. 

S. Purushothaman, C. Toumazou, C.-P. On, Protons and single nucleotide polymorphism detection a simple use for the Ion Sensitive Field Effect Transistor, Sensors and Actuators B Chemical 114 (2006) 964-968. 

Moody GJ, Thomas JDR, Slater JM (1988) Modified poly (vinyl chloride) matrix membranes for ion-selective field effect transistor sensors. Analyst 113 1703-1707... 

Matsuura K, Asano Y, Yamada A, Narus K (2013) Detection of Micrococcus Luteus biofilm formation in microfluidic environments by pH measurement using an ion-sensitive field-effect transistor. Sensors 13 2484-2493... 

Gardies F., Jaffrezic-Renault N., Martelet C, Perrot H., Valleton J.M. and Alegret S. (1990) Microenzyme field effect transistor sensor using direct covalent bonding of urease. Anal. Chim. Acta, 231, 305-308. 

Sanchez J, Beltran A, Alonso J, Jimenez C, del Valle M (2000) Development of a new ion-selective field-effect transistor sensor for anionic surfactants application to potentiometric titrations. Anal Chim Acta 382 157-164... 

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