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

•Selections of aptamer using the SLEX process.•Intercalation of ruthenium(II)-complex in aptamer.•Sensing of amyloid-β peptide using the luminescence technique.•Inhibition of amyloid-β fibril formation.

Aggregation of amyloid-β (Aβ) peptide has been known to be pathologically associated with Alzheimer and dementia diseases. Amyloid-β 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-β. 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-β monomers, the luminescence intensity of Ru(II) complex is reduced due to the strong interaction of aptamer with amyloid-β monomer/small oligomers. Furthermore, present study implies that our system has ability to inhibit the formation of amyloid-β 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-β aggregation in the clinical applications.

Graphical abstractSensing and inhibition of amyloid-β-fibril formation using ruthenium(II)-complex intercalated aptamer system is achieved successfully.Figure optionsDownload full-size imageDownload as PowerPoint slide