Detection of glycated hemoglobin (HbA1c) based on impedance measurement with parallel electrodes integrated into a microfluidic device

This paper proposes a sensor for glycated hemoglobin (HbA1c) detection based on impedance measurement. The sensor contains a pair of parallel facing electrodes integrated into a microfluidic device. A pair of parallel facing electrodes is fabricated to characterize the impedance change and determine the concentration of HbA1c. A self-assembled monolayer (SAM) of thiophene-3-boronic acid (T3BA) is used for modifying the gold electrodes. Non-faradaic electrochemical detection of surface-bound HbA1c with no redox indicator added is conducted by utilizing the capacitive property as a sensing signal. The performance of the HbA1c sensor was investigated by impedance analyzer and the impedance changes approximately logarithmically with the concentration of HbA1c in the range of 10–100 ng/μL. The proposed detection method has potential for use in point-of-care diagnostics and can be used for the detection of various biomolecules.