Novel Method for the Determination of Haemoglobin Phenotypes by Cyclic Voltammetry using Glassy Carbon Electrode

• Published in: International journal of electrochemical science 2009-11, Vol.4 (11), p.1593-1606
• Main Authors: Ogunlesi, M., Okiei, W., Akanmu, A.S., Popoola, T., Okafor, K., Akore, O.
• Format: Article
• Language: English
• Subjects: cyclic voltammetry; glassy carbon electrode; Phenotypes
• ISSN: 1452-3981; 1452-3981
• DOI: 10.1016/S1452-3981(23)15248-5

Haemoglobin is the oxygen transporter within the red blood cell. The oxygenation reaction is accompanied by release or uptake of protons depending on the pH. The electroactive nature of the reaction between haemoglobin and oxygen renders the binding study suitable for investigation by electrochemical method. Haemoglobin samples prepared from blood samples of known phenotypes were diluted with 0.2M acetate buffer, pH 5.0, to give stock solutions of concentration 2 x 10-5 mol. Fe/dm3. Aliquots were drawn and diluted with the buffer and cyclic voltammetry was carried out under nitrogen using glassy carbon/Ag, AgCl/Pt electrode system. 1.4 x 10-7 mol.Fe.dm-3. The values of peak current obtained were in the range of 3.1 – 3.6 μ A for HbA, 1.7 – 2.2 μA for HbAS, 1.2 – 1.6 μA for HbS and 2.5 – 3.00 μA for HbAC in the fixed range of concentrations of the haemoglobins. These values were used to identify the phenotypes of several haemoglobins successfully. The values of the peak current are sufficiently distinct to allow for rapid determination of these phenotypes. The method is simple and faster than the conventional electrophoretic method and removes the need to use standards once the characteristic values of peak current have been established. The good correlation between peak current and concentration also provides an accurate determination of the concentrations of haemoglobin samples.