Analyte sensor

Inventors

Shah, Rajiv • Liang, Bradley • Wolfe, Katherine • Messer, Ellen K • Pendo, Shaun M

Assignees

Percusense LLC

Abstract

A working electrode measuring the presence of an analyte is described as one embodiment. The working electrode includes a working conductor with a reactive surface that is operated at a first potential. The working electrode further includes a first transport material with properties that enable analyte flux to the reactive surface. Additionally, the working electrode has a second transport material with properties that enable reactant flux to the reactive surface, wherein the analyte flux and the reactant flux are in dissimilar directions.

Core Innovation

The invention relates to an in vivo electrochemical analyte sensor using a working conductor with a sensing surface portion and a reactive region exposed through an insulation layer window or opening. A multilayer enzyme layer is disposed on the sensing surface portion, with the enzyme layer filling the window or opening and protruding above the insulator top surface. A multilayer raised boss protrudes above the insulator and covers the enzyme layer, and the raised boss includes a first transport material and a second transport material arranged to control transport toward the reactive region.

The core structure creates a multilayer transport pathway in which the first transport material is permeable to a target analyte, including transport through one or more exposed lateral surfaces, while the second transport material is permeable to a reactant and impermeable to the target analyte. The enzyme layer and the complementary transport materials act together so that the target analyte and the reactant are directed toward the sensing region in controlled and dissimilar ways. The target analyte and the reactant flux are separated by their permeability properties and by the spatial geometry of the multilayer raised boss.

The invention further includes electrode geometries such as an aperture/via and a boss/raised protrusion, including structures in which enzyme and reactant/analyte transport are managed to mitigate effects of metabolically active/occluding cells and reaction byproducts. The multilayer design is described as enabling “factory-calibrated” sensing without correction factors and as facilitating complete electrochemical consumption of reaction byproducts, including hydrogen peroxide. Additional refinements include multilayer placement and flux pathways that reduce interference effects and maintain calibration/linearity across conditions such as oxygen levels, including multi-analyte sensor variations and pseudo-reference electrode formation.

Claims Coverage

The document provides two independent claim sets. Across these independent claims, four inventive areas are tied to controlling analyte flux and reactant flux toward a reactive sensing surface using permeability-selective first and second transport materials.

Both independent claims center on a raised boss/multilayer transport architecture that uses a first transport material permeable to a target analyte and a second transport material permeable to a reactant but impermeable to the target analyte, while exposing a sensing or reactive region through an insulator window or opening. The first independent claim incorporates an enzyme layer filling the window and a second transport material sealing the first transport material over the window; the second independent claim incorporates a first fill material rising above the insulation and covered by first and second transport materials arranged to permit analyte and reactant flux in different permeability-selected pathways.

Stated Advantages

Documented Applications