Assay of Biomarkers for Alzheimer's Disease by Surface Plasmon Resonance

Alzheimer's disease (AD) is one of the neurodegenerative diseases characterized by cognitive dysfunction and behavioral impairment. Early diagnosis of AD serves as a viable means to avoid the onset and progression of the disease. Due to the remarkably lower expression levels of AD biomarkers in cerebrospinal fluids and serum samples, sensitive and specific analytical methods are highly demanded. Surface plasmon resonance (SPR) is ultrasensitive to the refractive index or thickness change at the metal surface, which enables real-time and label-free assay of target biomolecules. In this review, we summarize the advances on assay of AD biomarkers including amyloid beta, tau protein, apoE proteins and apoE genes, and BACE1 by SPR, with emphasis on the analytical performances concerning anti-fouling and signal amplification strategies and real sample applications.