Exploring Interactions of Aptamers with Aβ40 Amyloid Aggregates and Its Application: Detection of Amyloid Aggregates

The exhaustive investigating interactions between recognition probe and amyloid aggregates, especially simultaneous recog-nition event, is challenged and crucial for the design of biosensing probes and further diagnosis of amyloid diseases. In the present work, the interactions of aptamers (Apts) with β-amyloid (Aβ) aggregates were explored thoroughly by single mole-cule force spectroscopy (SMFS). Indeed, it was found that the interaction of aptamer1 (Apt1)-amyloid aggregates was dif-ferent from that of aptamer2 (Apt2)-Aβ40 aggregates at the single-molecule level. Especially, the interaction force of Apt1-Aβ40 fibril showed double distinguishing Gaussian fitting. While the only unimodal distribution of force histogram was dis-played for the interactions of Apt2-Aβ40 oligomer, Apt2-Aβ40 fibril and Apt1-Aβ40 oligomer. More intriguingly, two Apts could bind to amyloid aggregates simultaneously. With the assist of two Apts recognition, a novel sensitive dual Apt-based surface plasmon resonance (SPR) sensor us...