LAUSR

Abstract In this work, an ultra-sensitive amyloid beta oligomer (AβO) sensor is presented in the detection range at atomolar level. A hierarchical gold dendrite (AuD) was electrochemically prepared on a gold substrate. Poly(pyrrole-3-carboxylic acid) [PPy-3-COOH] was electrodeposited on AuD to maintain the outstanding electrochemical properties, such as high conductivity and large surface area. After immobilization of the cellular prion protein (PrPC) bioreceptor through amide bond formation, the electrochemical sensor was incubated in gradient concentrations of AβO. The impedance response of the dendritic PPy-3-COOH/PrPC biosensor showed a proportional relationship to the increase of AβO concentration from 10−9 to 10 nM. The sensitivity at an atomolar level and high selectivity to AβO can be used in the diseased mice and blood test for the early diagnosis of Alzheimer’s disease.