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) 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 to 10 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.