Electrode-containing device with capillary transport between electrodes

In a device for determining the activity of an ionic analyte of a liquid, said device including a pair of solid, generally flat electrodes each constructed to generate an electrical potential that is proportional to the activity of an ionic analyte of a contacting quantity of such a liquid, and flow control means for directing flow of respective quantities of two such liquids each to a different one of said electrodes and to a junction between said liquids;

• the improvement wherein said flow control means includes
• (a) two opposed liquid transport surfaces extending from a first location disposed adjacent one of said electrodes to a second location adjacent the other of said electrodes, said surfaces being spaced apart a distance effective to induce capillary flow between said surfaces of introduced liquid and to create a transport zone, said transport zone being in liquid communication with said electrodes and comprising a void zone with fibers in an amount that is from 0 to 5% of the total volume of said zone;
• and
• (b) means defining first and second liquid passageways extending from an exterior surface of said device to said zone;
• whereby each of said liquids, when deposited in a different one of said passageways, respectively flows into contact with an electrode and through said transport zone to form a junction with the other liquid intermediate said first and second locations.

In a device for determining the activity of an ionic analyte of a liquid, said device including a pair of solid electrodes each constructed to generate an electrical potential that is proportional to the activity of an ionic analyte of a contacting quantity of such a liquid, and flow control means for directing flow of such liquid to at least one of said electrodes;

• the improvement wherein said flow control means includes
• (a) two opposed liquid transport surfaces extending from a first location disposed adjacent one of said electrodes to a second location adjacent the other of said electrodes, said surfaces being spaced apart a distance effective to induce capillary flow between said surfaces of introduced liquid and to create a transport zone, said transport zone being in liquid communication with said electrodes and comprising a volume containing fibers in an amount no greater than 5% of the total volume of said zone;
• and
• (b) means defining a liquid passageway extending from an exterior surface of said device to said zone;
• whereby a quantity of such liquid deposited in said passageway flows into contact with an electrode.

A multi-analyte test device for the analysis of a plurality of different ionic analytes in a quantity of a liquid, the device comprising,

• a first sheet,
• a second covering sheet, said sheets having opposing surfaces,
• means for spacing apart said sheets a distance effective to induce capillary flow between said surfaces of introduced liquid and to create a transport zone, said zone further including fibers in an amount that is from 0 to 5% of the total volume of said zone, one of said sheets including means permitting introduction of a quantity of a test liquid and a reference liquid into said zone, and
• a plurality of electrically isolated electrodes disposed in liquid communication with said zone, at least a first one of said electrodes comprising a test composition specific to the analysis of one of said analytes, and at least a second of said electrodes comprising a test composition specific to the analysis of a different one of said analytes, and
• vent means for permitting air to exit from said zone ahead of advancing liquid.