Nanoparticle-based multiplex biosensor utilising dual dielectrophoretic forces for clinical diagnosis of Alzheimer's disease

The significant correlation between amyloid-beta (A beta) and tau accumulated in the brain and the levels observed in plasma means that the quantification of plasma A beta and tau is gaining attention as an alternative to conventional Alzheimer's disease (AD) diagnostic methods, such as neuroimaging and psychological memory evaluation. However, there remain limitations, such as low accuracy and reproducibility of AD diagnosis using plasma A beta and tau quantification in clinical samples. Here, we propose an interdigitated microelectrode (IMEs)-based impedimetric biosensor that uses polystyrene beads (PS) and dielectrophoretic (DEP) force and demonstrate its clinical applicability in AD diagnosis. In the quantification of A beta and tau present in 1% standard plasma as well as in phosphate-buffered saline (PBS), the biosensor showed almost more than 2-fold higher sensitivity compared to the reference without PS and DEP force. Furthermore, by quantifying the levels of A beta and tau in the clinical plasma samples, we successfully distinguished between clinically diagnosed AD patients and normal controls with high accuracy (p < 0.0001). These results suggest that our biosensor has high applicability and excellent potential for the clinical diagnosis of AD.

Automated summary

The correlation between A beta and tau levels in plasma and brain accumulation has led to increased interest in quantifying these biomarkers in plasma as an alternative method for diagnosing Alzheimer's disease. A biosensor utilizing IMEs, PS, and DEP force showed high sensitivity and accuracy in distinguishing between AD patients and normal controls in clinical plasma samples. This technology has great potential for improving the clinical diagnosis of AD.