The importance of early Alzheimer’s disease (AD) detection has been recognized to diagnose people at high risk of AD. The existence of intra/extracellular beta-amyloid (Aβ) of brain neurons has been regarded as the most archetypal hallmark of AD. The existing computed-image-based neuroimaging tools have limitations on accurate quantification of nanoscale Aβ peptides due to optical diffraction during imaging processes. Therefore, we propose a new method that is capable of evaluating a small amount of Aβ peptides by using photo-sensitive field-effect transistor (p-FET) integrated with magnetic force-based microbead collecting platform and selenium(Se) layer (thickness ~700 nm) as an optical filter. This method demonstrates a facile approach for the analysis of Aβ quantification using magnetic force and magnetic silica microparticles (diameter 0.2~0.3 μm). The microbead collecting platform mainly consists of the p-FET sensing array and the magnet (diameter ~1 mm) which are placed beneath each sensing region of the p-FET, which enables the assembly of the Aβ antibody conjugated microbeads, captures the Aβ peptides from samples, measures the photocurrents generated by the Q-dot tagged with Aβ peptides, and consequently results in the effective Aβ quantification.

Date Published: 20 May 2013
PDF: 4 pages
Proc. SPIE 8879, Nano-Bio Sensing, Imaging, and Spectroscopy, 887903 (20 May 2013); doi: 10.1117/12.2017797

Published in SPIE Proceedings Vol. 8879:
Nano-Bio Sensing, Imaging, and Spectroscopy
Shin Won Kang; Seung-Han Park; Luke P. Lee; Ki-Bong Song; Yo Han Choi, Editor(s)