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.