摘要:
An electrochemical detector can be powered partly, or entirely by voltages generated by the sensor. Using either active circuits or a passive component which produces a predetermined voltage drop in the respective sensor, two electrode consumable anode oxygen sensors can be provided which do not evolve hydrogen during operation.
摘要:
A method of measuring a sample that includes at least one reactant that can be oxidised and reduced between at least one working electrode and a counter electrode. The method involves: applying across the working and counter electrodes a cycle of at least three pulses, and measuring current at the working electrode during each pulse, wherein the at least three pulses comprise at least one over-potential pulse that has an amplitude equal to or greater than an oxidation or a reduction peak potential of the reactant; at least one under-potential pulse of amplitude less than the at least one over-potential pulse, and at least one other over-potential pulse or under-potential pulse.
摘要:
A biosensor system determines an analyte concentration of a biological sample using an electrochemical process without Cottrell decay. The biosensor system generates an output signal having a transient decay, where the output signal is not inversely proportional to the square root of the time. The transient decay is greater or less than the -0.5 decay constant of a Cottrell decay. The transient decay may result from a relatively short incubation period, relatively small sample reservoir volumes, relatively small distances between electrode surfaces and the lid of the sensor strip, and/or relatively short excitations in relation to the average initial thickness of the reagent layer. The biosensor system determines the analyte concentration from the output signal having a transient decay.
摘要:
The invention relates to a device for the measurement of hydrogen peroxide and optionally other biomarkers in a gaseous mixture, and in particular to a microfabricated device. The device comprises hydrogen peroxide capturing means and an electromechanical sensor comprising a sensing element in direct contact with the capturing means. The device further comprises means to measure the potential of the sensing element and/or the current through it as a result of a changing hydrogen peroxide concentration in the gaseous mixture. The device also comprises cooling/heating means for cooling and/or heating the capturing means. The device is preferably applied for online measurement of the hydrogen peroxide content in exhaled air.
摘要:
The present invention relates to a method for proportioning nitrate and/or nitrite ions in a solution using a copper electrode, said method being characterized in that it is carried out in constant potential mode and moreover in that it includes the steps of: i. applying a first potential to the copper electrode so as to reduce the copper oxides present on the surface of the metal copper electrode; ii. applying a second potential to the copper electrode so as to oxidize the metal copper formed in Step i into cupric ions; iii. applying a third potential to the copper electrode so as to reduce the copper oxides possibly formed in Step ii, Steps i through iii being carried out in a support electrolyte; and iv. proportioning the nitrate and/or nitrite ions of a solution to be analyzed by means of immersing the copper electrode, obtained in Step iii, in said solution to be analyzed while applying a fourth potential to the copper electrode so as to reduce the nitrate and/or nitrite ions, the support electrolyte of Steps i through iii, and the solution to be analyzed in Step iv, having a substantially neutral pH.
摘要:
A sensor includes a housing, at least two electrodes within the housing, an electrolyte providing ionic conductivity between the electrodes and a vent member including a first section including a portion extending through a passage in the housing. The vent member also includes at least one extending member connected to the first section that extends through at least a portion of an interior of the housing. The first section of the vent member is porous so that gas can diffuse from the interior of the housing to an exterior of the housing via the vent member.
摘要:
The method according to the invention consists of generating an electrochemical signature of the analyzed substance(s), obtained by carrying out a numerical pseudo-titration and to express the result of the measurements in antioxidant power units. It involves the processing of a current-potential response of the oxidation of the analyzed substance(s) by a predefined mathematical dimensionless function representing a virtual and ideal oxidizing agent. The method is useful for the identification and/or detection and/or titration of antioxidant substances in the tested material, including directly on wet biological tissues.
摘要:
Procédé de mesure de la concentration globale en ions d'un fluide corporel qui comporte l'application d'une tension continue et stable entre des première et seconde électrodes (5, 6) d'une cellule de mesure de la concentration globale en ions d'un fluide corporel de manière à provoquer l'apparition de réactions électrochimiques d'hydrolyse de l'eau du fluide corporel, au niveau desdites première et seconde électrodes (5, 6), la mesure d'un courant d'hydrolyse engendré par lesdites réactions électrochimiques d'hydrolyse de l'eau et la détermination de la concentration globale ionique du fluide corporel par comparaison avec une courbe d'étalonnage définie au préalable. La cellule de mesure comporte un canal fluidique (1) ayant une section interne inférieure ou égale à 1,5 mm.