Low-Cost Polyphenol–Polypyrrole Molecularly Imprinted Sensor for Point-of-Care Alzheimer’s Detection
Ajith Mohan Arjun, Sudhaunsh Deshpande, Guoyi Liu, Daimei Miura, Krzysztof Pawlak, Takahiko Tokuda, Makoto Higuchi, Miyu Matsumoto, Tomoko Umemura, Kaori Tsukakoshi, Sanjiv Sharma
Abstract
High Resolution Image Download MS PowerPoint Slide There is an urgent need for rapid, affordable diagnostics for Alzheimer’s disease (AD), particularly those that can detect phosphorylated Tau 181 (p-tau181)─a key biomarker─directly in plasma. We present a scalable, label-free electrochemical biosensor fabricated on a printed circuit board platform, integrating a novel nanomolecularly imprinted polymer transducer based on a polyphenol red–polypyrrole composite. This platform enables sensitive detection of p-tau181 in undiluted plasma, serum, and clinical AD samples using a custom-designed potentiostat and machine learning-assisted classification. The sensor achieves a detection limit of 498 fg mL –1, a sensitivity of 8.99 μA/pg mL, and an area under the ROC curve (AUC) of 0.84 in clinical samples, comparable to the single molecule array (SIMOA) assay (AUC = 0.91), but at a fraction of the cost. This integrated platform, validated in real patient samples, demonstrates significant advancement toward accessible, point-of-care diagnostics for early AD detection.