Methods for the detection and diagnosis of malaria using an electrochemical sensor

1. A method for diagnosing malaria in a subject comprising:

introducing a test sample containing hemoglobin from the subject into a reaction cell including a primary electrode and a reference electrode;

adding hydrogen peroxide to the reaction cell;

measuring a current, voltage and/or resistance between the primary electrode and the reference electrode; and

comparing the level of the measured current, voltage and/or resistance of the test sample to a reference level, wherein a difference between the reference level and the level of the measured current, voltage and/or resistance indicates the presence of malaria in the subject.

2. The method of claim 1 , wherein the electrodes are each independently made of or coated by a material selected from gold, platinum, palladium, silver, carbon, copper, iridium, cobalt, nickel, or indium tin oxide.

3. The method of claim 2 , wherein the primary electrode is made of or totally or partially coated with nickel.

4. The method of claim 3 , wherein the hemoglobin is immobilized to the primary electrode.

5. The method of claim 2 , wherein the primary electrode is a platinum electrode with a sputtered nickel coating.

6. The method of claim 2 , wherein the reference electrode is an Ag/AgCl electrode.

7. The method of claim 1 , wherein the reaction cell further comprises a counter-electrode.

8. The method of claim 7 , wherein the counter-electrode is a platinum wire.

9. The method of claim 1 , wherein the test sample is whole blood.

10. The method of claim 9 , wherein introducing the test sample into the reaction cell is by adding whole blood to the phosphate buffered saline solution.

11. The method of claim 1 , wherein hydrogen peroxide is added to the reaction cell at a final concentration from about 10 to about 200 mM.

12. The method of claim 1 , wherein measuring the current generated between the primary electrode and the reference electrode is by cyclic voltammetry.

13. The method of claim 12 , wherein the potential is repetitively cycled from about −0.5 to about 0.5 V at a scan rate of 100 mV per second.

14. The method of claim 1 , wherein the reference level is a measured current, voltage, and/or resistance of a control sample.

15. The method of claim 14 , wherein a statistically significant difference between the test sample and the control sample indicates the presence of malaria in the subject.

16. A method for diagnosing malaria in a test sample of hemoglobin from a subject, the method comprising:

introducing the test sample into a first and a second reaction cell, each reaction cell comprising a primary electrode and a reference electrode;

adding hydrogen peroxide to the reaction cells;

measuring a first current generated between the primary electrode and the reference electrode in each reaction cell;

adding inositol hexaphosphate to the first reaction cell and 2,3-diphosphoglycerate to the second reaction cell; and

measuring a second current generated between the primary electrode and the reference electrode in each reaction cell,

wherein the absence of a change between the first current and the second current in each reaction cell indicates a diagnosis of malaria in the subject.

17. The method of claim 16 , wherein (i) an increase between the measured first current and the second current in the first reaction cell; (ii) a decrease between the measured first current and the second current in the second reaction cell; or (iii) both (i) and (ii) indicates that the subject does not have malaria.

18. The method of claim 16 , wherein the inositol hexaphosphate is added to the reaction cell at a final concentration from about 50 to about 250 μM.

19. The method of claim 16 , wherein the 2,3-diphosphoglycerate is added to the reaction cell at a final concentration from about 1 to about 3 mM.