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) 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 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 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.