▎ 摘　　要

Amyloid-beta (All) oligomers have been become believable biomarkers for predicting and diagnosing Alzheimer's disease (AD). Herein, an ultrasensitive electrochemical assay for detection of All oligomers was built based on the Au nanoparticles-modified vertical graphene/carbon cloth (Au-VG/CC) as substrate electrode and in-situ synthesized copper nanoparticles (CuNPs) as signal probes. For the biosensor preparation, the VG/CC film was firstly treated by the electrodeposition of Au nanoparticles, and the Au-VG/CC electrode provided large surface area and high conductivity. Then the residues 95-110 of cellular prion protein (PrPC) as the specific receptor for All oligomers were immobilized on the Au-VG/CC electrode surface by the Au-S bond. After the selective recognition to All oligomers, the poly(thymine)-templated CuNPs as the electrochemical probes were introduced by the design of aptamers. This assay for All oligomer detection showed a good performances including ultrahigh sensitivity with a low detection limit of 3.5 pM, excellent specificity, and great stability. This biosensor also presented feasibility for sensing All oligomers in serum samples of AD patients, and would contribute to understand the role of All oligomer as a biomarker for the early diagnosis of AD.