An Electrochemical HbA1c Immunosensor With a Simple Electrode of Gold Nanoparticle Monolayer

This study developed a novel electrochemical glycosylated hemoglobin (HbA1c) immunosensor. Polyethylene terephthalate (PET) was used as a substrate. After gold (Au) film sputtering on the PET surface, 1,6-hexanedithol with thiol groups on both terminals was used as an intermediary to attach a monolayer of uniformly distributed Au nanoparticles (AuNPs) to the Au thin film to form a nanostructured electrode. HbA1c antibodies were successfully immobilized on the AuNP monolayer via the self-assembled monolayer (SAM) approach. To mimic a real clinical detection environment, a calibration curve for HbA1c detection was performed in a mixture solution containing heparin sodium, red blood cell (RBC) lysis buffer, artificial human serum, and hemoglobin. The experimental results revealed that the proposed HbA1c immunosensor detected HbA1c in a linear range from 2500 to 10 000 ng/mL with a limit of detection of 2253 ng/mL. The developed HbA1c-sensing chip offers the advantages of simple operation, low cost, short detection time, and provides high feasibility for clinical application.