An electrochemical sensing platform based on gold nanostars for the detection of Alzheimer's disease marker Aβ oligomers (Aβo)

Abstract

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by the accumulation of amyloid-beta (Aβ) peptides in the brain. Among the different forms of Aβ, oligomers (Aβo) are considered the most toxic and have been implicated in AD pathology. However, the accurate detection of Aβo remains challenging due to their low abundance and structural complexity. In this study, we propose an electrochemical sensing platform based on gold nanostars (AuS) for the detection of Aβo in AD. The AuS were functionalized with a peptide probe (PrPc) that specifically interacts with Aβo. The PrPc-AuS sensing platform exhibited high sensitivity and selectivity for Aβo detection. The electrochemical impedance spectroscopy (EIS) analysis showed significant changes in impedance upon binding of Aβo to the PrPc-AuS surface, providing quantitative information about the Aβo concentration. The platform demonstrated a linear detection range of 5–200 pM with a detection limit of 2 pM, meeting the requirements for clinical detection. This electrochemical sensing platform offers a promising approach for the early diagnosis and monitoring of AD, contributing to the development of point-of-care diagnostics for neurodegenerative diseases.

Keywords

• Alzheimer's disease
• Aβ oligomers
• Electrochemical sensing
• Gold nanostars
• Peptide probe