A direct comparison of amperometric gas sensors with gas-diffusion and ion-exchange membrane based electrodes

Knake, René; Jacquinot, Patrick; Hauser, Peter C.

doi:10.1039/b105527p

Cited by 20 publications

(6 citation statements)

References 25 publications

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“…The determination of NO is not trivial due to its spontaneous oxidation to NO 2 - and NO 3 - . Moreover, there have been numerous reports in the literature describing novel methods for NO detection, many of which involve modified electrodes for amperometric measurements. − In this work, we have tried a simplified approach to measuring NO amperometrically by simply modifying a glassy carbon electrode in a parallel flow cell with Nafion. The chemical nature of Nafion allows NO to pass to the electrode surface but does not allow NO 2 - or NO 3 - to reach the electrode surface .…”

Section: Resultsmentioning

confidence: 99%

Detection of ATP-Induced Nitric Oxide in a Biomimetic Circulatory Vessel Containing an Immobilized Endothelium

Kotsis

Spence

2002

Anal. Chem.

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Conditions for the adhesion of bovine pulmonary artery endothelial cells (bPAECs) in microbore tubing of 250-microm i.d. are described. When immobilized to the lumen of microbore tubing, these cells represent a mimic of a circulatory vessel's endothelium. The microbore tubing is coated with 100 microg mL(-1) fibronectin in order to promote bPAEC adhesion to the lumen of the tubing. A series of micrographs of the cells inside of the tubing indicates that approximately 3.5 h is necessary for cell adhesion. In this study, adenosine triphosphate (ATP) is used to induce the release of nitric oxide from the endothelium mimic. The endothelium-derived NO is detected amperometrically at a parallel flow cell containing a glassy carbon working electrode modified with Nafion. Results indicate that detectable amounts of NO are only produced by the endothelium mimic when ATP is present in the buffer. The typical concentration of NO produced by the endothelium mimic upon the introduction of 100 microM ATP is approximately 0.80 microM. Based on the injection volume of ATP and the estimated number of cells on the tubing lumen, this value corresponds to approximately 1 amol of NO/cell. Moreover, shear stress alone does not provide the agonistic effect required for NO production in the submicromolar range.

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Section: Resultsmentioning

confidence: 99%

Detection of ATP-Induced Nitric Oxide in a Biomimetic Circulatory Vessel Containing an Immobilized Endothelium

Kotsis

Spence

2002

Anal. Chem.

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“…Electrochemical methods also enable real-time in situ measurement without requiring periodic sampling and they have proven effective for measuring numerous trace airborne targets such as CO, CO 2 , NO, NO 2 , SO 2 and O 2 . [4][5][6][7] While the electrochemical oxidation of methane is thermodynamically favorable, it is kinetically slow. In order to obtain an appreciable rate of electrooxidation for methane, hot acid electrolytes (at 80 to 180 C) must generally be employed with a platinum (Pt) electrocatalyst.…”

Section: Introductionmentioning

confidence: 99%

Methane–oxygen electrochemical coupling in an ionic liquid: a robust sensor for simultaneous quantification

Wang

Guo

Baker

et al. 2014

Analyst

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Current sensor devices for the detection of methane or natural gas emission are either expensive and have high power requirements or fail to provide a rapid response. This report describes an electrochemical methane sensor utilizing a non-volatile and conductive pyrrolidinium-based ionic liquid (IL) electrolyte and an innovative internal standard method for methane and oxygen dual-gas detection with high sensitivity, selectivity, and stability. At a platinum electrode in bis(trifluoromethylsulfonyl)imide (NTf2)-based ILs, methane is electro-oxidized to produce CO2 and water when an oxygen reduction process is included. The in situ generated CO2 arising from methane oxidation was shown to provide an excellent internal standard for quantification of the electrochemical oxygen sensor signal. The simultaneous quantification of both methane and oxygen in real time strengthens the reliability of the measurements by cross-validation of two ambient gases occurring within a single sample matrix and allows for the elimination of several types of random and systematic errors in the detection. We have also validated this IL-based methane sensor employing both conventional solid macroelectrodes and flexible microfabricated electrodes using single- and double-potential step chronoamperometry.

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“…Small changes in RH did not affect the signals, and we would not expect an RH dependence for this experiment as we would in Nafion electrolyte sensors which are RH dependent. 33 Although some reports have contained effects of RH signals from aqueous electrochemical sensors, we believe these to be simply effects of dilution or spurious changes in electrode hydration. Fig.…”

Section: No and No 2 Cv-inmentioning

confidence: 98%

Amperometric Sensing of NO[sub x] with Cyclic Voltammetry

Roh

Stetter

2003

J. Electrochem. Soc.

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Cyclic voltammetry ͑CV͒ techniques were used to measure the concentration of nitric oxide ͑NO͒ and nitrogen dioxide (NO 2 ) in air using an amperometric gas sensor. A porous gold membrane working electrode in sulfuric acid electrolyte was used with a counter electrode of bare Pt wire and quasi-reference electrode of electrodeposited Pt on a Pt wire. The anodic peak current (i pa ) was proportional to the concentration of NO at various bias sweep rates. The limit of detection was about 4.8 ppm for NO in air or 31 ppm for NO 2 in air for the CV methods. A parameter related to the diffusion coefficient and membrane permeability can be determined from CV measurements and was at the high range, 2.4 ϫ 10 Ϫ4 cm 2 s Ϫ1 , of reported values of diffusion constants. Simple models of combined effects of gas and liquid mass-transport and electrokinetic current limiting mechanisms complicate explanation of observed currents with porous gas electrodes.Nitric oxide, NO, is a human hormone necessary for healthy metabolic processes at parts per billion levels, and NO inhalation is now used to treat some conditions, but at high levels it can damage the human respiratory system. 1 The U.S. Occupational Safety and Health Administration and Department of Labor recommended exposure limit is 25 ppm NO in air. Symptoms of excess NO exposure are eye, nose, and throat irritations, drowsiness, and unconsciousness. Chronic health effects are methemoglobinemia, central nervous system effects, and delayed lung damage. 2 NO is formed in processes of combustion and found in effluents from coal-fired power plants and automobiles. 3,4 NO 2 can also cause adverse health effects 5 and causes environmental impact when reacting with water vapor in the atmosphere to contribute to acid rain. Therefore, sensitive and selective detection methods for these gases are required.Detection methods from colorimetric to electrochemical have been reported for NO, and references to electroanalytical approaches 6-10 can be found, but it has been some time since the earliest amperometric gas sensors ͑AGS͒ for NO and NO 2 were reported 9 in this journal. This early commercial NO/NO 2 sensor had a large 25 cc electrolyte reservoir and a design adapted from the amperometric ethanol 11 and CO 12,13 sensors of the time that used a composite Pt/tetrafluoroethylene ͑TFE͒ porous fuel cell-type electrode. The early NO sensor replaced the working electrode ͑WE͒ of the CO sensor with a powdered Au/TFE composite electrode to avoid interference from CO. Selectivity was achieved by reducing NO 2 at a potential too cathodic for NO oxidation and too anodic for NO reduction. 6,9 Since then, this system for ambient NO/NO 2 detection has been studied and used in several different embodiments. Later an electrode of powdered Au on Nafion was built 14 and the performance of this system was characterized and compared 7 to a thin-film low surface area ͑LSA͒ Au electrode on Nafion, both at constant potential. It was found that the LSA electrode offered a faster response and parts per billion...

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A direct comparison of amperometric gas sensors with gas-diffusion and ion-exchange membrane based electrodes

Cited by 20 publications

References 25 publications

Detection of ATP-Induced Nitric Oxide in a Biomimetic Circulatory Vessel Containing an Immobilized Endothelium

Detection of ATP-Induced Nitric Oxide in a Biomimetic Circulatory Vessel Containing an Immobilized Endothelium

Methane–oxygen electrochemical coupling in an ionic liquid: a robust sensor for simultaneous quantification

Amperometric Sensing of NO[sub x] with Cyclic Voltammetry

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