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.
This article describes a novel method for detection of amyloid-β (Aβ) peptide that utilizes a photo-sensitive field-effect
transistor (p-FET). According to a recent study, Aβ protein is known to play a central role in the pathogenesis of
Alzheimer’s disease (AD). Accordingly, we investigated the variation of photo current of the p-FET generated by the
magnetic beads conjugated with Aβ peptides which are placed on the p-FET sensing areas. Additionally, in order to
amplify the output signal, we used the lock-in amplifier (LIA) and confirmed the generating the photo current by a small
incident light power under 100 μW. It means that it is possible to simply detect a certain protein using magnetic beads
conjugated with Aβ peptide and fluorescent label located on the p-FET device. Therefore, in this paper, we suggest that
our method could detect tiny amounts of Aβ peptide for early diagnosis of AD using the p-FET devices.