Alcohol sensor

Safety Systems. A safety system is provided with built in safety shutdowns and emergency stop buttons. Crash buttons are located in the laser room, the laser table enclosure and the dome. The laser system is tied into the Observatory emergency stop system. Included both in the laser room and on the laser table are surveillance cameras, heat exchangers, alcohol sensors and fire detectors. In addition to personnel safety features, extensive interlocks have been installed in the laser to prevent the operator from inadvertently damaging it. 

In recent years further concepts have been developed for the construction of polymer-based diodes, requiring either two conjugated polymers (PA and poly(A-methyl-pyrrole) 2 > or poly(A-methylpyrrole in a p-type silicon wafer solid-state field-effect transistor By modifying the transistor switching, these electronic devices can also be employed as pH-sensitive chemical sensors or as hydrogen or oxygen sensors 221) in aqueous solutions. Recently a PPy alcohol sensor has also been reported 222). 

Most microhotplate-based chemical sensors have been realized as multi-chip solutions with separate transducer and electronics chips. One example includes a gas sensor based on a thin metal film [16]. Another example is a hybrid sensor system comprising a tin-oxide-coated microhotplate, an alcohol sensor, a humidity sensor and a corresponding ASIC chip (Application Specific Integrated Circuit) [17]. More recent developments include an interface-circuit chip for metal oxide gas sensors and the conccept for an on-chip driving circuitry architecture of a gas sensor array [18,19]. 

Kim SJ, Jeon BH, Choi KS (1999) Improvement of the sensitivity by UV light in alcohol sensors using porous silicon layer. In CAS 99 Proceedings of the international semiconductor conference, Sinaia, Romania, 2 475 78... 

Alcohol Sensor. On-line measurements of ethyl alcohol concentration in culture broth are required in fermentation industries. A microbial electrode consisting of immobilized yeasts or bacteria, a gas permeable Teflon membrane, and an oxygen electrode was prepared for the determination of methyl and ethyl alcohols(7). 

Unidentified bacterium and Trichosporon brassicae were used for the methyl and ethyl alcohol sensors, respectively. The microorganisms were adsorbed on a porous acetyl cellulose membrane. 

Adsorption temperature, effect on TPD spectra of oxygen on Pd-doped tin(IV) oxide, 74,75 Airborne chemicals, detection and identification, 299-307 Alcohol sensors, general discussion, 333... 

The extreme sensitivity of the visible absorption spectrum to small changes in the surrounding medium has made this betaine dye a useful molecular probe in the study of micellar systems [298, 299, 443-445], mieroemulsions and phospholipid bilayers [299], model liquid membranes [300], polymers [301, 446], organic-inorganie polymer hybrids [447], sol-gel matrices [448], surfaee polarities [449-451], and the retention behaviour in reversed-phase liquid chromatography [302]. Using polymer membranes with embedded betaine dyes, even an optical alcohol sensor has been developed [452]. 

S. T. Dubas, C. lamsamai, P. Potiyaraj, Optical alcohol sensor based on dye-Chitosan poly electrolyte multilayers. Sens. Actuators, B, Chem 113, 370-375 (2006). 

Because of the analogy of the AOD reaction to that of GOD, Clark in 1972 had already suggested an alcohol sensor based on AOD. Guilbault and Nanjo (1975a) described an H202-sensing AOD electrode with a detection limit of 0.01 mg/ml. 

The cofactor of ADH, NAD+, may not be replaced by other electron acceptors. Malinauskas and Kulys (1978) attempted to construct a reagentless alcohol sensor by coimmobilizing ADH with dextran-bound NAD+ by a dialysis membrane in front of an oxygen electrode. The O2 consumption was indicated via the reoxidation of NADH by NMP+. The system has also been used to measure NAD+ with high sensitivity. In... 

Torstensson et al. (1980) attached the cofactor directly to the active center of ADH in order to further integrate the reaction components in an alcohol sensor. During substrate conversion the cofactor was regenerated by anodic oxidation at a carbon electrode. Yao and Musha (1979) immobilized NAD+ covalently on the carbon surface. ADH reacts with the immobilized cofactor and electrons are shuttled to the electrode by a mediator. 

Torsi, L. et al., Alkoxy-snbstituted polyterthiophene thin-fihn-transistors as alcohol sensors. Sens. Actuators B, 98, 204, 2004. 

Tan O. K., Cao W., and Zhu W., Alcohol sensor based on a non-equilibrium nano-structured xZr02-(l-x)a-Pe203 solid solution system. Sens. Actuators B, 63, 129-134,... 

Dexmer J., Leroy C. M., Binet L., et al.. Vanadium oxide-PANI nanocomposite-based macroscopic fibers ID alcohol sensors bearing enhanced toughness, Chem. Mater., 20(17), 5541-5549, 2008. 

N. J. Pinto, I. Ramos, R. Rojas, P.-C. Wang, and A. T. Johnson Jr., Electric response of isolated electrospun polyaniline nanofibers to vapors of aliphatic alcohols. Sensors Actuat. B, 129, 621-627 (2008). 

Du, X.-Y. Anzai. J. Osa, T. Motohashi, R. Amperometric alcohol sensors based on protein multilayers composed of 25. avidin and biotin-labeled aleohol oxidase. Electroanalysis... 

Fig. 13 Direct electron transfer in an alcohol sensor based on QH-ADH entrapped within a polypyrrole film.

Torsi, L., M.C. Tanese, N. Cioffi, M.C. Gallazzi, L. Sabbatini, and P.G. Zambonin. 2004. Alkoxy-substituted polyterthiophene thin-film-transistors as alcohol sensors. Sens Actuators B 98 204-207. 

Josowicz, M., and J. Janata. 1986. Suspended gate field effect transistors modified with polypyrrole as alcohol sensor. Anal Chem 58 514. 

Chen J, Naglak T, and Wang HY (1992) An amperometric alcohol sensor on chemically permeabilized methylo-tropic microorganisms. Biotechnology Progress 8 161-164. 

Fig. 8.2 Comparison of (i) sensor response to 500 ppm CO in dry air and (2) time response for sensors fabricated using the three binder recipes. Sensor A SnOj + hydroxypropyl celliiose + isopropyl alcohol. Sensor B SnO + ethyl cellulose + a-terpineol soln. Sensor C TEOS + ethanol...

Innocenzi P., Martucci A., Guglielmi M., Bearzotti A., Traversa, E., Pivin J.C. Mesoporous silica thin films for alcohol sensors. J. Eur. Ceram. Soc. 2001b 21 1985-1988... 

In addition to generating electrical power, fuel cells are also the basis of some types of sensors. One of the most successful is the fuel cell-based alcohol sensor - the breathalyser (Figure 2.5). This measures the concentration of alcohol in the air that someone breathes out of his or her lungs. It has been shown that this is directly proportional to the concentration of alcohol in the blood. The basic chemistry is that the alcohol (ethanol) reacts in a simple fuel cell to give a (very small) voltage. In theory the ethanol could be fully oxidised to CO2 and water. However, the ethanol is probably not fully reacted and is only partially oxidised to ethanal. 

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