Multi-Stage Microfluidic Capture Arrays for Detecting Various Alzheimer's Disease Biomarkers in Saliva

The diagnosis of Alzheimer's disease (AD) at early stage is urgent for the clinical treatment. However, the methods of detecting multiple AD related markers with noninvasive sampling are still limited, which hinders their wide applications among potential patients. Here, we present a microfluidic chip with capture arrays to isolate and analyze immunomagnetic beads conjugated with AD salivary biomarkers. Through the design of a three-stage microfluidic capture array, magnetic beads combined with different biomarkers can captured at corresponding sections for high-resolution characterization. Finite element simulation was used to validate the capture efficiency. The lactoferrin with concentration comparable to AD patients was effectively analyzed using the fabricated microfluidic chip. These results indicate the proposed platform to be a potential non-invasive method to detect multiple AD markers by one-time injection of saliva samples with high sensitivity.