A Novel Electrochemical-Biosensor Microchip Based on MWCNTs/AuNPs for Detection of Glycated Hemoglobin (HbA1c) in Diabetes Patients

This study reports an electrochemical sensor based on multiwalled carbon nanotubes/gold nanoparticles (MWCNTs/AuNPs) for detection of total hemoglobin (Hb) and glycated hemoglobin (HbA1c) in blood samples. Measurement of glycated hemoglobin percentage (%HbA1c) is crucial to the monitoring of glycemia in diabetes patients. The %HbA1c, which refers to the concentration ratio of HbA1c to total hemoglobin (Hb), has been widely used for accurate determination of stage-wise diabetes. The gold nanoparticles (AuNPs) used in the sensor were synthesized using a biological method employing passion fruit peel extracts. The resulting AuNPs are spherical with diameter approximately 18 nm, and these can be mixed with MWCNTs in various ratios to form MWCNTs/AuNPs composites. TEM imaging indicates that gold nanoparticles decorate the surface of the MWCNTs. Coating of a screen-printed carbon electrode (SPCE) with MWCNTs/AuNPs affords the novel MWCNTs/AuNPs/SPCE electrode, which exhibits a linear response over a 0.186–2.044 g dl⁻¹ HbA1c concentration range, with the correlation value of 0.96. The electrode can reliably be utilized for detection of total Hb and HbA1c in blood samples, which highlights its promise as a reliable approach for sensitive point-of-care testing (POCT) of HbA1c in diabetes patients.