Device and methods of using device for detection of hyperammonemia

A biosensor comprising:

• at least a first and second vessel configured for receiving a sample from a point exterior to the biosensor;
• a fluid exchange opening positioned between the first and the second vessel;
• a membrane positioned across or over the fluid exchange opening;
• and
• a catalyst in liquid phase or solid phase a hypohalite in liquid phase;
• an alkali buffer in liquid phase;
• a phenolic reagent in liquid phase or solid phase;
• and
• a fluid circuit comprising, in fluid communication:
• the first and second vessel;
• a reagent conduit;
• and a detection vessel positioned distal from the first and second vessel;
• wherein the catalyst is sodium nitroprusside or a salt thereof, and, if the catalyst is in solid phase, the biosensor comprises from about 5.8 to about 7.3 micrograms of sodium nitroprusside or a salt thereof in solid phase;
• and, if the catalyst is in liquid phase, the sodium nitroprusside or a salt thereof is at a concentration greater than 8.4 μM.

A kit comprising a solid support that comprises:

• at least a first and second vessel;
• a fluid exchange opening positioned between the first and the second vessel;
• at least a first conduit in fluid communication with at least the first vessel, the first conduit configured to receive a fluid from a point external to the biosensor;
• and
• a membrane positioned at the fluid exchange opening;
• a catalyst in liquid phase or solid phase;
• a hypohalite in liquid phase;
• an alkali buffer in liquid phase;
• a phenolic reagent in liquid phase or solid phase;
• and
• a fluid circuit comprising, in fluid communication:
• the first and second vessel;
• a reagent conduit;
• and a detection vessel positioned distal from the first and second vessel;
• wherein the catalyst is sodium nitroprusside, and, if the catalyst is in solid phase, the biosensor comprises from about 5.8 to about 7.3 micrograms of sodium nitroprusside or a salt thereof in solid phase;
• and, if the catalyst is in liquid phase, the sodium nitroprusside or a salt thereof is at a concentration greater than 8.4 μM;
• and
• wherein the membrane comprises an ionomer.