Electrochemiluinescence monitoring the interaction between human serum albumin and amyloid-β peptide

Human serum albumin (HSA) is a major interaction-partner of amyloid-β (Aβ) peptide in the plasma and can modulate the aggregation of Aβ. In this work, an efficient smart electrochemiluminescence (ECL) sensing platform was applied to determine the ability of HSA to bind different Aβ40 aggregate species. Specifically, HSA was firstly adopted as a linker and self-assembled on the gold electrode, Aβ peptide were subsequently anchored onto the HSA-modified electrode through the recognition by HSA. CdS quantum dots (CdS QDs) modified with Aβ40 aptamer as the ECL substrate were then captured on the electrode via the specific coordination between Aβ40 and the aptamer. The present ECL sensor showed different ECL response in the presence of Aβ40 with different aggregation states. The ECL platform exhibited a signal-on response with the introduction of Aβ40 monomer in a concentration-dependent manner from 10 fM to 0.1 nM. Furthermore, the inhibition effect of several phenols on the aggregation of Aβ40 was also investigated. This work potentially provided a feasible strategy of sensing platforms for Aβ detection and further understanding of the mechanism by which HSA modulates the aggregation of Aβ.