Electrochemical Direct Detection of Glycated Hemoglobin (HbA1c) by Immobilized Glucose Oxidase on ZnO Nanostructures

Document Type : Original Article


Advanced Micro and Nano Devices Lab., Faculty of New Sciences and Technologies, University of Tehran, North Kargar St. Tehran, Iran


Electrochemical method is used for glycated hemoglobin (HbA1c) detection using a new configuration of working electrodes coated by ZnO nanorods. HbA1c reflects the average plasma glucose over two months. In this work, HbA1c is directly detected electrochemically without any proteolytic digestion for the first time. ZnO nanorods modify the working electrode to increase the surface of sensing, leading to amplifying the electrochemical signal and providing a stable enzyme bed for GOx immobilization. The limit of detection (LOD) is 0.32 μg/μl which can be achieved in 40 seconds as the sensor's response time. The range of detection is 0.32 µg/µl (0.21% of HbA1c)-22.4 µg/µl (14.93% of HbA1c) that covers the standard diagnosis range. Due to embedded nanostructures, a small amount of about 2 μl GOx solution and 50 nl of blood is required for detection. The low response time makes this sensor suitable for fast tests such as diabetic population enumeration and screening. 


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