Clinically Accurate Diagnosis of Alzheimer's Disease via Single-Molecule Bioelectronic Label-Free Profiling of Multiple Blood Extracellular Vesicle Biomarkers.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with no cure, making early diagnosis critical for mitigating its impact. Blood extracellular vesicles (EVs) hold promises as biomarkers for AD diagnosis, but current detection technologies lack the sensitivity and multiplexing capabilities needed for efficient diagnosis. Here, a novel label-free bioelectronic platform is presented based on an organic electrochemical transistor (OECT) integrated with a microelectrode array (MEA) for ultrasensitive detection of AD biomarkers in blood EVs, including amyloid-β (Aβ1-40 and Aβ1-42), total tau (t-tau), and phosphorylated tau (p-tau181). This platform achieves a detection limit as low as the zeptomolar (zM) level, enabling the detection of single-molecule targets. It provides a comprehensive multiplexed diagnostic model capable of delivering results within 20 min. Notably, the systematic integration of multiple AD biomarkers in blood EVs is demonstrated to significantly enhance diagnostic accuracy. This study presents a novel EVs-based multiplexed diagnostic model for AD, correctly classifying all clinical samples (n = 40), far exceeding the accuracy of a single biomarker. With its high sensitivity and rapid turnaround, this platform enables reliable AD diagnosis and holds the potential for tracking disease progression, offering a transformative tool to combat the societal burden of AD.