Embodiments of this invention disclose new second generation uric acid-sensing electrodes at least characterized by chemically bonding both uricase and the redox mediator to an electrode. The produced electrodes can be long-term stably used without losing activity. The developed electrode has been successfully applied for the analysis of uric acid (UA) in healthy human urine specimens which exhibits very good analysis accuracy and precision without too much interference. Therefore, the developed electrodes have the potential for clinical applications.

Testing of the performance of an electrochemical meter used to measure the presence of an analyte in a biological sample, particularly glucose in whole blood, includes introducing a control solution containing a predetermined amount of the analyte and a predetermined amount of an internal reference compound. The internal reference compound is selected such that it is oxidized at a potential greater than that used to oxidize the analyte, thereby making it possible to distinguish the control solution from a biological sample.

In vivo monitoring devices and systems for enzymes and/or analytes including devices having a reactant reservoir are provided.

Provided herein are methods involving an autocatalyzed looped relay amplification mechanism for detecting an analyte in a sample. The method is useful for detecting very low abundance analytes.

Analyte sensors featuring an enzyme system comprising diaphorase and a NAD-dependent dehydrogenase may be utilized to detect inhibitors of diaphorase, provided that the transfer of electrons to a working electrode is rate-limiting with respect to the diaphorase. Such analyte sensors may comprise a sensor tail comprising at least a first working electrode, a first active area disposed upon a surface of the first working electrode, and an analyte-permeable membrane overcoating at least the first active area. The enzyme system comprises NAD, reduced NAD, or any combination thereof; a NAD-dependent dehydrogenase, such as NAD-dependent glucose dehydrogenase; and diaphorase. Inhibitors of diaphorase that may be detected include, for example, warfarin, dicoumarol, and similar compounds. A second active area may be present to facilitate detection of an analyte differing from the inhibitor of diaphorase.

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.

The present disclosure provides redox mediators having two tridentate ligands and analyte sensors comprising such redox mediators. The present disclosure further provides methods of using such analyte sensors for detecting one or more analytes present in a biological sample of a subject.

A method for sensing an analyte utilizing a sensor having a working electrode, the method includes providing the working electrode with an analyte-specific enzyme and a redox mediator, providing the working electrode to the analyte, accumulating charge derived from the analyte reacting with the analyte-specific enzyme and the redox mediator for a set period of time, connecting the working electrode to circuit after the set period of time, and measuring the signal from the accumulated charge.

The present disclosure provides an analyte sensor for use in detecting glutamate. In certain embodiments, a glutamate-responsive active site of a presently disclosed analyte sensor includes an enzyme system comprising glutamate dehydrogenase and diaphorase disposed upon a surface of a working electrode. The present disclosure further provides methods for detecting glutamate using the disclosed analyte sensors.

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.