Naked-eye detection of amyloid aggregates using gold nanoparticles modified with amyloid beta antibody.

We developed a rapid method for estimating the amyloid beta (Aβ)-conformation state related with Alzheimer's disease. We prepared gold nanoparticle (AuNP)-Aβ antibody conjugates treated with bovine serum albumin to stabilize their dispersibility in a buffer. The prepared AuNPs were precipitated in the presence of Aβ aggregates, such as oligomers and fibrils. Aβ monomers did not precipitate AuNPs. The formation of AuNP precipitates by Aβ aggregates could be confirmed by the naked eye within 1 h.