Abstract

Alzheimer’s disease (AD) is the most prevalent cause of dementia, and detection of biomarkers such as t-tau, phospho-tau and beta-amyloid, represents an emerging method for AD screening since the expression profile of biomarkers can vary from the normal range at around 15-20 years before any dementia symptoms. We develop a direct and ultrasensitive assay based on immunoreaction between the target and corresponding antibody followed by protein turn-on fluorophore labelling to detect these protein biomarkers for AD in body fluids. Herein, we improve the detection sensitivity of the assay mentioned above by reducing the non-specific background level by introducing AuNPs as fluorescence quenchers. Lower limit of detection and higher sensitivity can be achieved which holds great promise for the early diagnosis of AD.