An electrochemical aptasensor based on stimulus response and signal amplification strategy for the detection of Amyloid-β oligomers

In this study, an aptasensor was prepared by stimuli-responsive and signal amplification strategy to detect Amyloid-β oligomers (AβO). ZIF-8 was directly carbonized to prepare nanoporous carbon without carbon precursor, and the samples obtained at different temperature were characterized. Porous carbon derived from ZIF-8 at 700℃ (ZC-700) with the best loading capacity was obtained as a nano-container, which was used to hold MB, and the aptamer acting with AβO. Aptamers were accumulated on the surface through π-π stacking to form a stimuli-responsive container. When the aptamer interacted with AβO, it would leave the surface of the container. Therefore, Methylene blue (MB) would run out of the pores of ZC-700, be captured by capture probe, and be enriched on glass carbon electrode (GCE) to realize signal amplification and complete detection. The sensor had a detection range of 50fM to 10 nM and a detection limit of 1.58fM. It also had a great performance in the actual sample, which was promising in the early diagnosis of Alzheimer's disease.