Detector in vitro analytes small volume using a diffusible or non-leachable redox mediator.

摘要

A detector for determining the concentration of an analyte in a fluid sample, the detector comprising: an electrode pair comprising a working electrode and a counter electrode, wherein at least a portion of the working electrode is an effective distance no more than 200 im a portion of the counter and, optionally, the counter electrode is a counter / reference electrode; optional reference electrode; a sample chamber for holding the sample fluid in electrolytic contact with the working electrode, counter electrode and reference electrode, the camera shows a measurement zone next to the working electrode if present, comprising the counterelectrode and the reference electrode, if present, dimensioned the measurement zone to contain a volume of no more than about 1 yl fluid sample and, optionally, the sample chamber is sized to contain no more than about 1 yl demonstrates fluid; and a touch sensitive analyte enzyme and a diffusible redox mediator disposed in the measurement zone; being configured and arranged so that the detector background signal generated by the diffusible redox mediator is no more than either: br / br / (a) five times a signal generated by oxidation or reduction of a physiologically normal average amount of analyte; or br / br / (b) five times a signal generated by oxidation or reduction of an amount corresponding to the average deviation from an average normal physiological amount of analyte analyte.