A non-invasive, reusable DNA-based electrochemical biosensor for Alzheimer's Disease biomarkers.

Aptonix is a DNA-based biosensor that detects Alzheimer's disease (AD) biomarkers by measuring electrical signals, like a molecular voltmeter. We engineer PAMAM dendrimers as 3D scaffolds displaying aptamer recognition elements tagged with methylene blue redox reporters. When a target molecule binds, the aptamer changes shape, inducing redox tag's movement and increasing electron transfer to the gold electrode, producing a measurable current increase via PCB-based potentiostat readout. Toehold-mediated strand displacement (TMSD) enables reversible aptamer exchange without electrode refabrication, creating a reconfigurable electrochemical aptasensor. The dendrimer's iron-sulfur cluster core amplifies signals while organizing aptamers at optimal surface densities, translating molecular computation principles into practical point-of-care diagnostics. Aptonix aims to provide a sensitive blood-based biosensor to detect AD biomarkers at early stages to improve prognosis.