1. Field of Invention
The present invention relates to an electrochemical method and a test strip for detecting a hemoglobin concentration, and more particularly to an electrochemical method and a test strip for detecting a hemoglobin concentration in a whole blood specimen.
2. Description of Related Art
In a blood test, except blood sugar and cholesterol, hemoglobin is also an important item. At present, methods for detecting the hemoglobin include a specific gravity method using copper sulfate for measuring the specific gravity of the whole blood; an oxidation-reduction reaction method using the “heme”, which has peroxidase activity; an immunological method using an antibody of HbA1 for detecting the hemoglobin in stool; a gas measuring method detecting the binding of carbon monoxide with hemoglobin; and a cyanmethemoglobin method, in which potassium ferricyanide (K3Fe(CN)6) converts hemoglobin into methemoglobin and further into cyanmethemoglobin with sodium cyanide (NaCN) or potassium cyanide (KCN), and then the absorbance is measured at a particular wavelength etc. However, the above methods still have many disadvantages.
For example, when an optical device is used for detection, a large amount of specimen is needed and specimens need to be pre-treated before the detection in order to avoid an inaccurate result owing to the interfered absorbance. The above test methods are not only time-consuming, but also need a large amount of blood or non-blood specimen. Furthermore, the unstable property of cyanmethemoglobin usually affects the accuracy of detection, and potassium cyanide is quite toxic.
Therefore, electrochemical detection, particularly, electrochemical test strip has gradually become an important method in biochemical tests because it is simply produced, low cost, widely used and portable. U.S. Pat. No. 7,138,041 discloses that a sensory strip is used in electrochemical detection. However, this patent is silent on how to improve the dissolution property of the electron mediator for detecting the hemoglobin in a specimen.
As a result, it is still desired to have an electrochemical method and a test strip for rapidly and accurately detecting hemoglobin in a small amount of specimen.