Alkaline Hematin-Based Disposable Electrochemical Sensor for Haemoglobin

Abstract

Estimating haemoglobin levels in the blood is crucial as it indicates various disease conditions, including anaemia, cancers, and liver, kidney, and lung diseases. This paper presents the fabrication of an electrochemical biosensor to estimate haemoglobin in alkaline conditions. The rifting of the quaternary structure of the Hb under high alkaline conditions paves the pathway for the formation of alkaline hematin. Graphite-kaolin clay composite electrocatalyst was synthesized and screen printed on a disposable electrode for the direct electrooxidation of alkaline hematin. The sensor exhibited high selectivity, linear responses over a concentration range from 10 to 80 μM, and a sensitivity of 43.26 µA µM-1 cm-2. The performance of the sensor was validated by testing with whole blood samples. The novelty of the work lies in the direct electrooxidation of alkaline hematin on the disposable screen-printed electrode without any cell separation or cell lysing steps.