Simutaneous Analysis of Alzheimer's Disease Biomarkers Using Cascaded Microfluidic Capture Arrays

In this study, we developed a microfluidic chip with a cascaded capture array (MiCCA) structure to analyze immuno-magnetic beads (MBs) conjugated with Alzheimer's disease (AD) salivary biomarkers. The chip features a three-level cascaded microfluidic capture array, enabling the sequential capture of MBs conjugated with different biomarkers. The MiCCA platform allows for mono-dispersion of MBs between structured microcolumn arrays, minimizing fluorescence dispersion and enabling high-resolution characterization. Using the MiCCA platform, we simultaneously analyzed the levels of AD-related biomarkers, lactoferrin (Lf), tau phosphorylated at threonine 181 (p-tau-181), and Amyloid β-protein 1-42 (Aβ 1-42) in the artificial saliva. The platform demonstrated a limit of detection (LOD) of <1 μg/ml for Lf, <10 pg/ml for p-tau181, and <1 pg/ml for Aβ1-42, with excellent specificity. These results suggest that the MiCCA platform holds promise as a rapid, highly sensitive, noninvasive method for detecting multiple AD biomarkers with different concentration ranges.