Embodiments of the invention provide an in-situ polymerization technique for creating a glucose sensor chemistry stack. An analyte sensor comprises a crosslinked polymer matrix in contact with an electrode. The crosslinked polymer matrix is formed by exposing ultraviolet (UV) light to a polymer matrix mixture comprising a plurality of hydroxyethyl methacrylate (HEMA) monomers, one or more di-acrylate crosslinkers, one or more UV photoinitiators, and an oxidoreductase. The oxidoreductase is covalently linked to the crosslinked polymer matrix. In typical embodiments, the oxidoreductase is a glucose oxidase-acrylate bioconjugate. In one or more embodiments, the analyte sensor apparatus further comprises a glucose limiting membrane positioned over the crosslinked polymer matrix. The glucose limiting membrane is formed by exposing ultraviolet (UV) light to a glucose limiting membrane mixture comprising a plurality of hydroxyethyl methacrylate (HEMA) monomers, one or more di-acrylate crosslinkers, one or more UV photoinitiators, ethylene glycol, and water.

The invention disclosed herein includes electrode compositions formed from processes that sputter metal in a manner that produces pillar architectures. Embodiments of the invention can be used in analyte sensors having such electrode architectures as well as methods for making and using these sensor electrodes. A number of working embodiments of the invention are shown to be useful in amperometric glucose sensors worn by diabetic individuals. However, the metal pillar structures have wide ranging applicability and should increase surface area and decrease charge density for catalyst layers or electrodes used with sensing, power generation, recording, and stimulation, in vitro and/or in the body, or outside the body.

The present invention provides a sensor head for use in an implantable device that measures the concentration of an analyte in a biological fluid which includes: a non-conductive body; a working electrode, a reference electrode and a counter electrode, wherein the electrodes pass through the non-conductive body forming an electrochemically reactive surface at one location on the body and forming an electronic connection at another location on the body, further wherein the electrochemically reactive surface of the counter electrode is greater than the surface area of the working electrode; and a multi-region membrane affixed to the nonconductive body and covering the working electrode, reference electrode and counter electrode. In addition, the present invention provides an implantable device including at least one of the sensor heads of the invention and methods of monitoring glucose levels in a host utilizing the implantable device of the invention.

An electrochemical cell includes a plurality of working electrode zones disposed, and defining a pattern, on a surface of the cell and at least one auxiliary electrode disposed on the surface. The auxiliary electrode may have a defined interfacial potential.

A method of measuring a quantity of a substrate contained in sample liquid is provided. This method can reduce measurement errors caused by a biosensor. The biosensor includes at least a pair of electrodes on an insulating board and is inserted into a measuring device which includes a supporting section for supporting detachably the biosensor, plural connecting terminals to be coupled to the respective electrodes, and a driving power supply which applies a voltages to the respective electrodes via the connecting terminals. One of the electrodes of the biosensor is connected to the first and second connecting terminals of the measuring device only when the biosensor is inserted into the measuring device in a given direction and has a structure such that the electrode becomes conductive between the first and second connecting terminals due to a voltage application by the driving power supply.

A detection system for determining alpha-methylacyl-CoA (AMACR) levels in a bodily sample includes at least one reaction solution for generating H.sub.2O.sub.2 upon combination with AMACR in the bodily sample and a biosensor for determining a level of generated H.sub.2O.sub.2. The reaction solution includes a (2R)-2-methylacyl-CoA epimer that can be chirally inverted by AMACR to a (2S)-2-methylacyl-CoA epimer and an enzyme that carries out beta oxidation with the (2S)-2-methylacyl-CoA epimer to generate hydrogen peroxide (H.sub.2O.sub.2).

An enzymatic sensor and processes for making an enzymatic sensor are disclosed. In some implementations, a sensor is provided that includes a gel-enzyme layer for reacting with an analyte of interest to create an electrical signal corresponding to a concentration of the analyte in a sample. In addition, a cushion layer formed on the gel-enzyme layer to attenuate the effects of mechanical perturbations on the gel-enzyme layer and its concomitant distortion of a signal output of the sensor.

A system for the electrochemical detection of triglyceride levels includes a test strip including an electrode and a counter electrode, the electrode and counter electrode located proximate to a sample reception area; and a coating on one of the electrode and counter electrode, the coating including a reagent coating for triglycerides.

Devices, assays and methods for detecting analytes in a sample are provided. Biosensor devices include a biosensor interface that includes enzyme-conjugated molecules, antibodies and an enzyme driven redox cycle coupled to an electrically conductive electrode for signal amplification. The biosensor devices are easily adaptable to a variety of assay formats, a variety of target analytes and provide real-time measurements combined with high sensitivity and high specificity for the analyte.

Test sensors, methods, and systems are described that include a first electrode pair having either two active electrodes or an inactive working electrode paired with an active counter electrode. These active electrodes are different than having an electron transfer mediator on an inactive electrode because in addition to the structural differences between an electrode directly in contact with the conductors of the test sensor verses a reagent coating, there are chemical and functional differences. The active electrodes are formed from an electrode core material including an element that loses or acquires electrons during the analysis and directly participates in the electrochemical reaction of the sample. As the active electrodes are insoluble in the sample during the analysis, an electrochemically stable potential is provided by the active electrodes that can reliably operate at higher operating potentials than conventional electron transfer mediator reagents coated on an inactive electrode.