Ultrasensitive Detection of Amyloid‑β Using Cellular Prion Protein on the Highly Conductive Au Nanoparticles–Poly(3,4-ethylene dioxythiophene)–Poly(thiophene-3-acetic acid) Composite Electrode

A highly sensitive electrochemical impedance sensor for amyloid beta oligomer (AβO) was fabricated using a cellular prion protein (PrP^C) bioreceptor linked with poly­(thiophene-3-acetic acid) transducer. An additional thin layer of poly­(3,4-ethylene dioxythiophene) embedded with gold nanoparticles was employed to provide high electrical conductivity and a large surface area. The sensing performace was investigated in terms of sensitivity and detection range. The fabricated sensor exhibited extremely low detection limit at a subfemtomolar level with a wide detection range from 10^–8 to 10⁴ nM and its utility was established in mice infected with Alzheimer’s disease (AD). The developed AβO sensor could be utilized for early diagnosis of AD.