On-chip, aptamer-based sandwich assay for detection of glycated hemoglobins via magnetic beads

Diabetes can be diagnosed and monitored by measurement of the cutoff ratio between glycated hemoglobins (HbA1c) and total hemoglobin (Hb), which does not require a fasting blood sample and is less influenced by biological variations. In this study, we combined the advantages of the microfluidic system and the selected low-cost, stable and specific aptamers and developed an integrated, aptamer-based microfluidic system for automatic glycated hemoglobin measurements. The detection process of human whole blood can be totally automated in this integrated microfluidic system. According to the experimental results, when compared to conventional bench-top manual assays, reagent consumption was significantly reduced by 75%, and the analysis time was reduced from 3.5h to 30 min. Besides, the novelty in this research also lies in the simultaneously performed two parallel assays for detection of Hb and HbA1c in a single chip. Therefore, this sensitive and low-cost aptamer-based microfluidic system may become a promising tool for point-of -care diagnosis of diabetes.