Investigation of the recognition interaction between glycated hemoglobin and its aptamer by using surface plasmon resonance

Glycated hemoglobin (HbA1c) has been widely explored as an important marker for monitoring and diagnosing diabetes. Due to the advantages of high selectivity , easy preparation, and convenient preservation of aptamers , research on glycated hemoglobin detection utilizing aptasensors has received much attention in recent years. However, factors such as the pH and the salt concentration of the solution and the structure of the aptamer could influence the interactions between HbA1c and the aptamer. In this study, the factors were evaluated using surface plasmon resonance (SPR). The results show that the pH and the salt concentration can greatly affect the formation of a complex between the aptamer and HbA1c. In the stereostructure of the aptamer, loop L1 may be an important motif for recognizing glycated hemoglobin. In addition, the best condition for detecting HbA1c was at pH 6, with a high sensitivity and a low limit of detection(LOD) (1.06 × 10 −3 RU nM /2.55 nM). The results also demonstrated that the use of an SPR aptamer biosensor can be a sensitive technique to improve the accuracy and correctness of HbA1c measurement.