Abstract: The present disclosure relates to a creatinine sensor comprising a first working electrode, a creatinine sensing layer on the first working electrode comprising a redox mediator, creatinine amidohydrolase, creatine amidinohydrolase, and sarcosine oxidase, and a hydrophilic polyurethane membrane overcoating the creatinine sensing layer. The creatinine sensor can further comprise a background sensing electrode that does not detect creatinine.

Abstract: The present disclosure provides an analyte sensor comprising a working electrode, a sensing layer disposed on at least a portion of the working electrode, and a hydrophilic polyurethane membrane overcoating at least the sensing layer, wherein the hydrophilic polyurethane is aliphatic, aromatic, or both aliphatic and aromatic. The hydrophilic polyurethane membrane limits the transport of mass to the sensing layer without the need to be crosslinked. With such membrane, the analyte sensor can provide consistent analyte measurements over a temperature range of about 22-42° C. The present disclosure is further related to a method of forming an analyte sensor comprising providing a working electrode, disposing a sensing layer on at least a portion of the working electrode, and coating at least the sensing layer with a hydrophilic polyurethane membrane, wherein the hydrophilic polyurethane is aliphatic, aromatic, or both aliphatic and aromatic.

Abstract: The present disclosure provides an analyte sensor for use in detecting aspartate and/or asparagine. In certain embodiments, an aspartate-responsive active site of a presently disclosed analyte sensor includes an aspartate oxidase disposed upon a surface of a working electrode. In certain embodiments, an asparagine-responsive active site of a presently disclosed analyte sensor includes an enzyme system comprising an aspartate oxidase and an asparaginase disposed upon a surface of a working electrode. The present disclosure further provides methods for detecting aspartate and/or asparagine using the disclosed analyte sensors.

Abstract: The present disclosure provides an analyte sensor for use in detecting potassium. In certain embodiments, an analyte sensor of the present disclosure includes at least two asparagine-responsive active areas, where each asparagine-responsive active area includes an asparaginase that exhibits a particular potassium dependency. In certain embodiments, an analyte sensor of the present disclosure includes at least two aspartate-responsive active areas, where each aspartate-responsive active area includes an aspartate oxidase that exhibits a particular potassium dependency. The present disclosure further provides methods for monitoring potassium levels, e.g., in vivo potassium levels, using the disclosed analyte sensors.