Publication

Journal	Proc. SPIE
Volume (Issue)	9129(912918)
Page(s)	1 - 9
Title of proceedings	Proc. SPIE
DOI	10.1117/12.2052842

The misfolding and aggregation of amyloid proteins has been assocd. with incurable diseases such as Alzheimer's or Parkinson's disease. In the specific case of Alzheimer's disease, recent studies have shown that cell toxicity is caused by sol. oligomeric forms of aggregates appearing in the early stages of aggregation, rather than by insol. fibrils. Research on new strategies of diagnosis is imperative to detect the disease prior to the onset of clin. symptoms. Here, we propose the use of an optical method for protein aggregation dynamic studies using a Bloch surface wave based approach. A one dimension photonic crystal made of a periodic stack of silicon oxide and silicon nitride layers is used to excite a Bloch surface wave, which is sensitive to variation of the refractive index of an aq. soln. The aim is to detect the early dynamic events of protein aggregation and fibrillogenesis of the amyloid-beta peptide Aβ42, which plays a central role in the onset of the Alzheimer's disease. The detection principle relies on the refractive index changes caused by the depletion of the Aβ42 monomer concn. during oligomerization and fibrillization. We demonstrate the efficacy of the Bloch surface wave approach by monitoring in real-time the first crucial steps of Aβ42 oligomerization. [on SciFinder(R)]