Point-of-care device for the colorimetric determination of hemoglobin and glucose-6-phosphate dehydrogenase in biological samples

1. A test strip for simultaneous colorimetric quantification of glucose-6-phosphate dehydrogenase (G6PDH) and hemoglobin (Hgb) in a biological sample, said test strip comprising superimposed membrane layers comprising:

a spreading layer capable of distributing or metering a biological sample across the surface of a primary membrane;

a primary membrane, said primary membrane being in direct contact with the spreading layer so that a biological sample applied to the test strip flows transversely across the spreading layer and then migrates vertically or horizontally into the primary membrane;

a secondary membrane for hemoglobin comprising a surfactant, an immobilizing mordant, sodium azide and sodium nitrite for producing azidomethemoglobin or a direct read of end-color of lysed red blood cells;

a secondary membrane for G6PDH comprising a surfactant, a mordant, glucose-6-phosphate as a substrate, and sodium nitrite;

wherein said secondary membranes are not in direct contact with each other but are in direct contact with said primary membrane;

an optical reagent membrane for hemoglobin in direct contact with said secondary membrane for hemoglobin, said optical reagent membrane for hemoglobin comprising a surfactant and being capable of removing small particulate cellular debris and providing a uniform color across the surface of the membrane;

an optical reagent membrane for G6PDH in direct contact with said secondary membrane for G6PDH, said optical reagent membrane for G6PDH comprising a surfactant, an electron mediator, nicotinamide adenine dinucleotide phosphate (NADP + ), and a bio-reactive indicator generating a signal which is proportional to liberated G6PDH in the biological sample,

wherein said optical membranes are horizontally segregated from each other, and

wherein said test strip provides a quantitative analytical range of 0.03 to 25.0 units G6PDH/(gram/dL Hgb).

2. The test strip of claim 1 wherein the primary membrane is a digestive membrane capable of hemolyzing red blood cells.

3. The test strip of claim 1 wherein the primary membrane contains sodium nitrite or an oxidizing agent to convert ferrous iron (Fe (2+) ) to ferric iron (Fe (3+) ).

4. The test strip of claim 1 , wherein the biological sample is whole blood, urine, or saliva.

5. The test strip of claim 1 wherein the biological sample is whole blood and the primary membrane comprises one or more hemolytic agents.

6. A test kit for simultaneous quantification of hemoglobin (Hgb) and glucose-6-phosphate dehydrogenase (G6PDH) in a biological sample, said test kit comprising the test strip as set forth in claim 1 .

7. A method for simultaneous quantification of hemoglobin (Hgb) and glucose-6-phosphate dehydrogenase (G6PDH) in a biological sample, said method comprising applying a biological sample to the spreading layer of the test strip as set forth in claim 1 and reading the results of the test strip which are able to simultaneously quantify the levels of hemoglobin (Hgb) and glucose-6-phosphate dehydrogenase (G6PDH) in the biological sample.

8. The method of claim 7 further comprises obtaining and applying the biological sample directly from the patient.

9. The method of claim 7 wherein the biological sample is whole blood, saliva, or urine.