High-Performance Screen-Printed OECT-Inspired with Encased Cassette Based on PEDOT:GO for Sensitive and Specific Electrochemical Aptasensing of Aβ–42 in Management of Alzheimer’s Disease

Recently, substantial interest has emerged in developing point-of-care diagnostic devices for Alzheimer's disease (AD), a progressive neurodegenerative disorder characterized by the accumulation of beta-amyloid (Aβ1−42) peptides that act as critical biomarkers for early detection. In response to the growing demand for noninvasive and accessible diagnostic tools, this study presents a highly sensitive organic electrochemical transistor-inspired biosensor for the detection of Aβ–42 in saliva. The device is based on a paper substrate modified with a PEDOT:GO composite and a Ag-Au nanocomposite, which together enhance electrical conductivity and improve the electrochemical response. A highly selective Aβ1−42-binding aptamer is immobilized on the sensor surface. This platform enables real-time signal amplification, allowing the detection of Aβ–42 over a dynamic range of 1 pg/mL to 10 μg/mL. This biosensor demonstrates excellent sensitivity, selectivity, and reproducibility, making it a potential tool for noninvasive, point-of-care detection. The use of artificial saliva as a diagnostic medium further enhances its applicability for early screening, especially in decentralized or resource-limited healthcare environments.