Simultaneous Monitoring of Amyloid-β (Aβ) Oligomers and Fibrils for Effectively Evaluating the Dynamic Process of Aβ Aggregation.

Herein, we provide a proof of concept for a novel strategy that targets the assessment of the aggregation of amyloid-β (Aβ) by simultaneously determining its oligomers (Aβo) and fibrils (Aβf) in one analytical system. By fabricating and combining two immunosensors for Aβo and Aβf, respectively, we constructed a two-channel electrochemical system. The ratio of Aβf to Aβo was calculated and taken as a possible criterion for evaluating the extent of aggregation. Thereby, the presence of and transformation between oligomers and fibrils were accurately probed by incubating the Aβ monomer for different times and then calculating the ratios of Aβf to Aβo. The applicability of this method was further validated by tracking the dynamic progress of Aβ aggregation in the cerebrospinal fluid and tissues of Alzheimer's disease (AD) rats, which revealed that the ratio of Aβf to Aβo in rat brain gradually increased with the progression of AD, which was indicative of the severity of peptide aggregation during this process. Overall, this study represents the first example of a quantitative strategy for precisely evaluating the aggregation process that is related to pathological events in AD brain.