Monitoring of early diagnosis of Alzheimer's disease using the cellular prion protein and poly(pyrrole-2-carboxylic acid) modified electrode

Amyloid-beta oligomers (AβΟ) are considered to be reliable biomarkers for the diagnosis of Alzheimer’ disease (AD), and the cellular prion protein (PrP^C) is identified as a receptor for AβO. We demonstrated a label and antibody-free electrochemical biosensor for the selective detection of AβO using an electrically conductive poly(pyrrole-2-carboxylic acid) (PPyCOOH) linking agent and PrP^C receptor. In the fabrication of the biosensor, each step was characterized by electrochemical impedance spectroscopy and cyclic voltammetry. The developed PrPc/PPyCOOH biosensor exhibited extremely low detection limit of 10⁻⁴ pM with high sensitivity which is desirable for the early diagnosis of AD. The sensing performance was further confirmed by the mice infected with AD. The proposed sensor emerged as a promising tool for the early detection of AβO.