Amyloid beta (Aβ) is one of most crucial neuropathological biomarkers in Alzheimer's disease (AD). Up to date, the relation between the progress of the disorder and the interchange of Aβ level in the blood is still controversial; however, increasing evidence for transport of Aβ across the brain blood barrier (BBB) provides the linkage between concentrations of Aβ in central nervous system (CNS) and blood plasma. Hence, quantifying the Aβ level in blood plasma is considered as an emerging diagnostic method for AD. Here, we describe an integrated molecular diagnostic system (iMDx) for Aβ detection based on a dark-field microscope with single nanoparticle resolution. We obtain a sensitive plasmonic sandwich immunoassay for Aβ detection with a single nanoparticle resolution. We quantify simultaneously Aβ 1-40 and Aβ 1-42 on chip and characterize selectivity. We demonstrate the function of sample-to-answer iMDx that enables the portable diagnosis for Aβ level from whole blood by plasma separation. Hence, proposed iMDx could be a promising point-of-care tool for an early diagnosis of AD.
Project end date: 09/02/16