A reagent composition containing GDH-PQQ as an enzyme-co-factor and screen-printed on working and counter electrodes of electrochemical biosensors, maintains activity of the enzyme reagents by proper selection of components. A preferred composition includes hydrophilic polymers, amorphous untreated silica, buffers, surfactants, and a mediator.

Systems and methods for sensing target molecules such as redox reactive agents, comprising a sample compartment and a sensing compartment being in fluid communication, are disclosed. A sensing compartment which comprises nanostructures to which a functional moiety is covalently attached and which is such that upon contacting a redox reactive agent a change in electrical property of the nanostructure occurs, and integration of such a sensing compartment with sensing systems as described herein are also disclosed. Methods of monitoring a metabolic activity of cells, and uses thereof, are also disclosed.

A device (200) for sensing a biofluid (18) includes at least one analyte-consuming sensor (220) for measuring at least a first analyte concentration of an analyte in the biofluid (18) and at least one additional component (248). The at least one additional component (248) maintains analyte-consuming sensor (220) measurements within 20% of the first concentration measurement if a biofluid (18) sample flow rate is less than or equal to 2 times a first biofluid (18) sample flow rate measurement as measured by the device (200). A method for sensing a biofluid (18) includes measuring a first analyte concentration of an analyte in the biofluid (18) using an analyte-consuming sensor (220), measuring a first biofluid sample flow rate, and maintaining a subsequent analyte concentration measurement within 20% of the first analyte concentration measurement when a subsequently measured biofluid (18) flow rate is less than or equal to 2 times the first biofluid sample flow rate.

Detection reagents, multi-analyte test elements, test systems, and multi-analyte measuring methods are provided. In particular, multi-analyte test elements have (1) a first working electrode and first counter electrode pair covered with a first analyte-specific reagent that includes an enzyme, a coenzyme and a first mediator and have (2) a second working electrode covered with a second analyte-specific reagent that includes an enzyme, a coenzyme and a second mediator, where the second mediator is different than the first mediator. The single counter electrode can be used as the counter electrode for both the first and second analyte measurements at their respective working electrodes. Moreover, the mediator concentrations, measurement ranges, and applied potential differences are not the same for each analyte-specific measurement.

A biosensor (1) is disclosed that may include at least one electrode surface (3); a reagent layer (5) disposed on top of the at least one electrode surface (3) and a reagent layer (5) formed thereon. The reagent layer (5) is formed according to the principles of the present invention, and may include a redox enzyme, a redox polymer, and a cross-linked gel. The reagent layer (5) is structured to act as a conductive matrix that traps the redox polymer and enzyme at the electrode surface.

Fluid collection devices, analysis instruments and methods for making and using same are disclosed. The fluid collection device is provided with a device and an electrochemical cell. The device has first and second walls defining a microfluidic channel, and a sample application port communicating with the microfluidic channel. The first wall and the second wall are spaced a distance less than 150 microns. The electrochemical cell is disposed on the first wall to contact a sample travelling through the microfluidic channel. The electrochemical cell comprising molecule receptors such that a physical property of the first electrochemical cell is effected upon one or more of the molecule receptors binding to an electroactive species within the sample.

Biosensors and biosensor systems are disclosed that have manganese (III) oxide (Mn.sub.2O.sub.3)-based electrodes that can attenuate interference of a detection signal resulting from an analyte-relevant reaction caused by undesired reaction of interferents in a sample. Methods are also disclosed for making and using the same.

The present invention provides members that produce on a large scale a coenzyme-linked glucose dehydrogenase which has excellent substrate-recognizing ability toward glucose while providing low action on maltose. The present invention relates to a polynucleotide encoding a soluble coenzyme-linked glucose dehydrogenase that catalyzes the oxidation of glucose in the presence of an electron acceptor and has an activity toward maltose of 5% or lower; a polypeptide encoded by the nucleotide sequence of the polynucleotide; a recombinant vector carrying the polynucleotide; a transformed cell produced using the recombinant vector; a method for producing a polypeptide comprising culturing the transformed cell and collecting from the cultivated products a polypeptide that links to FAD to exert the glucose dehydration activity; a method for determination of glucose using the polypeptide; a reagent composition for determination of glucose; and a biosensor.

The present invention provides members that produce on a large scale a coenzyme-linked glucose dehydrogenase which has excellent substrate-recognizing ability toward glucose while providing low action on maltose. The present invention relates to a polynucleotide encoding a soluble coenzyme-linked glucose dehydrogenase that catalyzes the oxidation of glucose in the presence of an electron acceptor and has an activity toward maltose of 5% or lower; a polypeptide encoded by the nucleotide sequence of the polynucleotide; a recombinant vector carrying the polynucleotide; a transformed cell produced using the recombinant vector; a method for producing a polypeptide comprising culturing the transformed cell and collecting from the cultivated products a polypeptide that links to FAD to exert the glucose dehydration activity; a method for determination of glucose using the polypeptide; a reagent composition for determination of glucose; and a biosensor.

The present invention provides members that produce on a large scale a coenzyme-linked glucose dehydrogenase which has excellent substrate-recognizing ability toward glucose while providing low action on maltose. The present invention relates to a polynucleotide encoding a soluble coenzyme-linked glucose dehydrogenase that catalyzes the oxidation of glucose in the presence of an electron acceptor and has an activity toward maltose of 5% or lower; a polypeptide encoded by the nucleotide sequence of the polynucleotide; a recombinant vector carrying the polynucleotide; a transformed cell produced using the recombinant vector; a method for producing a polypeptide comprising culturing the transformed cell and collecting from the cultivated products a polypeptide that links to FAD to exert the glucose dehydration activity; a method for determination of glucose using the polypeptide; a reagent composition for determination of glucose; and a biosensor.