A method for electrochemically measuring an amount of an oxidoreductase using a biosensor which includes a conductive part including two or more electrodes, and a reagent layer that is in contact with the conductive part and includes a substrate of the oxidoreductase and two or more types of mediators. A first mediator transfers, to a second mediator, electrons generated by a reaction between the substrate and the oxidoreductase, and a second mediator transfers, to the electrodes, the electrons transferred from the first mediator. The method includes bringing a sample containing an oxidoreductase into contact with a reagent layer; performing incubation for a predetermined period of time after the contact, to cause the second mediator to accumulate electrons; applying a voltage across the electrodes after the incubation; measuring an electric signal generated by the voltage application; and calculating an amount of the oxidoreductase based on the electric signal.

The present disclosure relates to an oxidation-reduction polymer which can be used in an electrochemical sensor, and particularly, in a polymer backbone of an electron transfer medium of the electrochemical sensor. More specifically, the present disclosure relates to: an oxidation-reduction polymer which can be used in a poly (allyl glycidyl ether)-based electrochemical sensor including a repeating unit derived from allyl glycidyl ether; and an electron transfer medium and an electrochemical sensor including same, wherein the oxidation-reduction polymer is advantageous in confirming the completion of reaction during manufacture, has high immobilization efficiency of the transition metal complex, has low possibility of having problems of toxicity and side effects, and can add various functions.

A reagent for detecting an analyte comprises a flavoprotein enzyme, a mediator such as a phenothiazine mediator, at least one surfactant, a polymer and a buffer. The reagent may be used with an electrochemical test sensor that includes a plurality of electrodes.

An electrochemical test device is provided having a base layer with a first electrode thereon and a top layer with a second electrode thereon. The two electrodes are separated by a spacer layer having an opening therein, such that a sample-receiving space is defined with one electrode on the top surface, the other electrodes on the bottom surface and side walls formed from edges of the opening in the spacer. Reagents for performing the electrochemical reaction are deposited on one of the electrodes and on the side walls of the sample-receiving space.

Devices and methods are employed to detect substances in a medium. The device comprises an electrogenic bacterium that selectively interacts with a substance to produce electrons. A portion of the electrons provides power to the device and a portion of the electrons generates a signal as an indication of the presence of a substance in the medium. The method comprises contacting the electrogenic bacterium of the device with a medium suspected of containing the substance and measuring the signal generated by the electrons.

The present disclosure relates to an oxidation-reduction polymer including a transition metal complex, which has a unique structure, and so can be prepared in a simpler step compared to a conventional method, and can increase the immobilization rate of the transition metal complex and facilitates the introduction of a functional group or a linker, a method for preparing the same and an electrochemical biosensor comprising the oxidation-reduction polymer.

An extraction system for testing microbial contamination includes a biocompatible outer vessel that has a side wall and a biocompatible suspension system that is positionable within an interior of the biocompatible outer vessel. The biocompatible suspension system includes a horizontal member on which a sample may be supported and a securement mechanism that is engagable with the side wall of the biocompatible outer vessel to maintain the suspension system at a desired position within the biocompatible outer vessel.

NADP-dependent oxidoreductase compositions, and electrodes, sensors and systems that include the same. Analyte sensors include an electrode having a sensing layer disposed thereon, the sensing layer comprising a polymer and an enzyme composition distributed therein. The enzyme composition includes nicotinamide adenine dinucleotide phosphate (NAD(P).sup.+) or derivative thereof; an NAD(P).sup.+-dependent dehydrogenase; an NAD(P)H oxidoreductase; and an electron transfer agent comprising a transition metal complex.

NADP-dependent oxidoreductase compositions, and electrodes, sensors and systems that include the same. Analyte sensors include an electrode having a sensing layer disposed thereon, the sensing layer comprising a polymer and an enzyme composition distributed therein. The enzyme composition includes nicotinamide adenine dinucleotide phosphate (NAD(P).sup.+) or derivative thereof; an NAD(P).sup.+-dependent dehydrogenase; an NAD(P)H oxidoreductase; and an electron transfer agent comprising a transition metal complex.

NADP-dependent oxidoreductase compositions, and electrodes, sensors and systems that include the same. Analyte sensors include an electrode having a sensing layer disposed thereon, the sensing layer comprising a polymer and an enzyme composition distributed therein. The enzyme composition includes nicotinamide adenine dinucleotide phosphate (NAD(P).sup.+) or derivative thereof; an NAD(P).sup.+-dependent dehydrogenase; an NAD(P)H oxidoreductase; and an electron transfer agent comprising a transition metal complex.