Sensing and inhibition of amyloid-beta based on the simple luminescent aptamer-ruthenium complex system

Abstract

Aggregation of amyloid-beta (A beta) peptide has been known to be pathologically associated with Alzheimer and dementia diseases. Amyloid-beta fibrils serve as an important target for the drugs development and diagnosis of neurodegenerative diseases. Herein, we report a new [Ru(dmbpy)(dcbpy)dppz)] complex (dmbpy; 4,4'-dimethyl-2,2'-bipyridine, dcbpy; 4,4'-dicorboxy-2,2'-bipyridine, dppz; dipyridophenazine) intercalated aptamer based recognition of amyloid-beta. Interestingly, aforementioned Ru(II) complex shows weak luminescence intensity in the aqueous medium but it shows strong luminescence intensity in the presence of RNA aptamer. Upon addition of amyloid-beta monomers, the luminescence intensity of Ru(II) complex is reduced due to the strong interaction of aptamer with amyloid-beta monomer/small oligomers. Furthermore, present study implies that our system has ability to inhibit the formation of amyloid-beta fibrils, which is confirmed from the AFM morphological structures in the absence and presence of aptamer. This work may contribute the rapid diagnosis and inhibition of amyloid-beta aggregation in the clinical applications.