Detection reagents and electrode arrangements for multi-analyte diagnostic test elements, as well as methods of using the same

A method of electrochemically measuring concentration or presence of one or more analytes of interest in a body fluid sample, the method comprising the steps of:

• applying a body fluid sample having or suspected of having the one or more analytes of interest to a diagnostic test element so that the body fluid sample is in fluidic contact with a detection reagent to hydrate the detection reagent, wherein the diagnostic test element includes:
• a cover;
• a non-conductive substrate comprising a capillary channel defined thereon and formed in part with the cover at a first end of the non-conductive substrate;
• a plurality of electrodes provided on the non-conductive substrate, the electrodes including a first working electrode including at least a portion thereof positioned in the capillary channel, a second working electrode including at least a portion thereof positioned in the capillary channel, and a single counter electrode associated with the first working electrode and the second working electrode and utilized in measurement of both a first analyte and a second analyte;
• a first detection reagent for detecting the first analyte comprising a first coenzyme-dependent enzyme or a substrate for the first enzyme, a first coenzyme, and a first mediator;
• and
• a second detection reagent for detecting the second analyte comprising a second coenzyme-dependent enzyme or a substrate for the second enzyme, a second coenzyme, and a second mediator;
• wherein the first detection reagent is positioned relative to the first working electrode and the counter electrode in an arrangement facilitating measurement of the first analyte with the first working electrode and the counter electrode, and the second detection reagent is positioned relative to the second working electrode and the counter electrode in an arrangement facilitating measurement of the second analyte with the second working electrode and the counter electrode;
• applying an electrical test sequence to the diagnostic test element via a test meter configured to interact with the diagnostic test element, wherein the test sequence comprises:
• a. a first fixed direct current (DC) component comprising a potential difference applied between the counter electrode and the first working electrode to measure a first analyte of interest;
• and
• b. a second fixed DC component comprising a potential difference applied between the counter electrode and the second working electrode to measure a second analyte of interest;
• measuring response information to each component of the electrical test sequence with the test meter;
• and
• determining one or more analyte concentrations with the test meter using the response information;
• wherein the first analyte is glucose and the second analyte is hydroxybutyrate;
• and
• wherein the first coenzyme-dependent enzyme is FAD-dependent glucose dehydrogenase, the first coenzyme is FAD, and the first mediator is N,N-bis(hydroxyethyl)-3-methoxy-4-nitrosoaniline hydrochloride (NA1144), and wherein the second coenzyme-dependent enzyme is FAD-dependent glucose dehydrogenase or a glucose oxidase, the second coenzyme is FAD or PQQ, and the second mediator is a ferricyanide or a nitrosoaniline other than NA1144 as the mediator.

A reagent system for detecting multiple analytes, comprising:

• a first detection reagent for detecting a first analyte comprising a first coenzyme-dependent enzyme or a substrate for the first enzyme, a first coenzyme, and a first mediator;
• and
• a second detection reagent for detecting a second analyte comprising a second coenzyme-dependent enzyme or a substrate for the second enzyme, a second coenzyme, and a second mediator, wherein the second mediator is distinct from the first mediator, and the first and second mediators are selected to facilitate use of the reagent system on a diagnostic test element comprising a single counter electrode utilized in measurement of both the first analyte and the second analyte;
• wherein the first coenzyme-dependent enzyme is FAD-dependent glucose dehydrogenase, the first coenzyme is FAD, and the first mediator is N,N-bis(hydroxyethyl)-3-methoxy-4-nitrosoaniline hydrochloride (NA1144), and wherein the second coenzyme-dependent enzyme is FAD-dependent glucose dehydrogenase or a glucose oxidase, the second coenzyme is FAD or PQQ, and the second mediator is a ferricyanide or a nitrosoaniline other than NA1144 as the mediator.