Abstract:

Objective To construct a label-free electrochemical immunosensor for the specific detection of glycated hemoglobin A_1c（HbA_1c）. Methods A 16 channel screen-printed carbon electrode（16-SPCE） was modified by HbA_1c antibody to prepare a label-free electrochemical immunosensor for the specific detection of HbA_1c. Cyclic voltammetry was used to detect the electrical signal of HbA_1c by 16-SPCE electrochemical immunosensor,and the detection conditions（the optimal coating concentration of HbA_1c antibody,the optimal incubation time of HbA_1c antigen,the electrochemical characteristics of the electrode and the performance of different modified electrodes） were optimized. A preliminary methodological evaluation was conducted. Results The optimal HbA_1c antibody coating concentration was 50 μg/mL,and the optimal HbA_1c antigen incubation time was 60 min. The linear range of HbA_1c was 1-50 μg/mL,and the linear equation was Y=0.199X+10.468（r=0.955）. The detection limit was 0.88 μg/mL,and 50 μg/mL bovine serum albumin（BSA）,50 μg/mL prostate-specific antigen（PSA） and 50 μg/mL glucose did not interfere with the detection of HbA_1c by 16-SPCE electrochemical immunosensor. The prepared immunoelectrode was stably placed at 4 °C for 5 d. The 16-SPCE electrochemical immunosensor was used to detect HbA_1c in the simulated serum samples. The current response values of each concentration were clearly distinguished,and the repeatability was good. Conclusions The constructed 16-SPCE electrochemical immunosensor has good electrochemical response,linear range and anti-interference ability.

Key words: Glycated hemoglobin A_1c, 16 Channel screen-printed carbon electrode, Electrochemical immunosensor