Light-Triggered Graphene/Black Phosphorus Heterostructure FET Platform for Ultrasensitive Detection of Alzheimer's Disease Biomarkers at the Zeptomole Level.

Due to the low concentration of amyloid-beta (Aβ) in plasma and the high content of interfering factors, the conventional detection method for the quantification of Aβ still faces the problem of insufficient limit of detection (LOD). In this work, we propose a new light-triggered graphene-black phosphorus heterostructure (G-BP) field-effect transistor (FET) biosensing platform that achieves a ​​marked​​ reduction in the LOD. The LOD for Alzheimer's disease (AD) biomarker Aβ₄₂ detection using the G-BP FET is as low as 235.1 zM (2.351 × 10^-19 M), which is the lowest value reported to date and is approximately 2 to 3 orders of magnitude lower than other reported biosensing platforms. The G-BP FET platform provides precise, real-time guidance for non-invasive early diagnosis, disease monitoring, and personalized treatment plans for AD. Moreover, this method has good scalability and potential applications in other areas, including early detection of cancer and other major chronic diseases.