A biosensor is for sensing analytes in a fluid. The biosensor may include a first structural layer having a first hydrogel, a second structural layer having a second hydrogel, and a bioactive region extending between the first structural layer and the second structural layer and having a third hydrogel. The biosensor may include a first electrode coupled to the bioactive region, and a second electrode coupled to the first structural layer and being spaced apart from the bioactive region. The second structural layer may have a through opening adjacent the bioactive region, and the bioactive region may be configured to be in fluid communication with an environment external to the biosensor for receiving the fluid comprising the analytes.

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.

A microneedle array device includes a substrate and an array of microneedles on the substrate. Each microneedle includes a redox enzyme and redox mediator and an electrically conductive layer on the substrate. The electrically conductive layer may extend partway up each microneedle exposing the tip thereof.

Embodiments of the present disclosure relate to NADP-dependent oxidoreductase compositions, and electrodes, sensors and systems that include the same. Also provided are methods for making the compositions and for detecting and/or measuring analytes with NADP-dependent oxidoreductase compositions.

The present invention relates to a method for removing oxygen, used in an electrochemical biosensor, and to a measurement system and a method for electrochemically determining a concentration of an analyte using said method.

A polypeptide comprising a residue substituted by a non-canonical amino acid (ncAA) is provided. Methods for: (a) transferring an electron to an electrode, by coupling the polypeptide to an electrode; and (b) quantifying the amount of an analyte e.g., glucose are also provided.

Described herein is an amperometric biosensor, e.g., chronoamperometric biosensor for the measurement of the concentration of nicotine. Also disclosed herein is a wearable nicotine biosensor device and a biosensor that detects nicotine in smoke. The biosensor disclosed herein comprises a nicotine-catalyzing enzyme, such as NicA2 or mutant NicA2 enzymes. Also described herein are systems comprising said amperometric biosensor, e.g., chronoamperometric biosensor and methods of using said chronoamperometric biosensor.

Analyte sensors responsive at low working electrode potentials may comprise an active area upon a surface of a working electrode, wherein the active area comprises a polymer, a redox mediator covalently bonded to the polymer, and at least one analyte-responsive enzyme covalently bonded to the polymer. A specific redox mediator responsive at low potential may have a structure of

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wherein G is a linking group covalently bonding the redox mediator to the polymer. A mass transport limiting membrane permeable to the analyte may overcoat the active area. In some sensor configurations, the mass transport limiting membrane may comprise a membrane polymer crosslinked with a branched crosslinker comprising three or more crosslinkable groups, such as polyethylene glycol tetraglycidyl ether.

Methods and analyte sensors including a sensor tail comprising at least a first working electrode and a second working electrode that are spaced apart from one another along a length of the sensor tail. A first active area is disposed upon a surface of the first working electrode and a second active area is disposed upon a surface of the second working electrode, the first active area and the second active area being responsive to different analytes. A mass transport limiting membrane is deposited upon the first active area and the second active area by sequential dip coating operations, and the mass transport limiting membrane comprises a bilayer membrane portion overcoating the first active area and a homogeneous membrane portion overcoating the second active area.

A method of making an electrochemical sensor strip that includes: depositing a first electrode on a base; depositing a second electrode on the base; applying a first layer onto the first electrode; and applying a second layer onto the second electrode. The first layer includes an oxidoreductase and a mediator. The second layer includes a soluble redox species.