Sensitive electrochemical immunosensor for α-synuclein based on dual signal amplification using PAMAM dendrimer-encapsulated Au and enhanced gold nanoparticle labels.

摘要: A novel electrochemical immunosensor for sensitive detection of α-synuclein (α-SYN), a very important neuronal protein, has been developed based on dual signal amplification strategy. Herein, G4-polyamidoamine dendrimer-encapsulated Au nanoparticles (PAMAM-Au nanocomposites) were covalently bound the poly-o-aminobenzoic acid (poly-o-ABA), which was initially electropolymerized electrode surface to perform abundant carboxyl groups. The formed platform, PAMAM-Au, proved provide numerous amino groups allow highly dense immobilization antigen, and facilitate improvement responses as well. Subsequently, enhanced gold nanoparticle labels ({HRP-Ab(2)-GNPs}) fabricated by immobilizing horseradish peroxidase-secondary antibody (HRP-Ab(2)) (GNPs). After an immunoassay process, {HRP-Ab(2)-GNPs} introduced onto surface, produced electrocatalytic response reduction hydrogen peroxide (H(2)O(2)) in presence enzymatically oxidized thionine. On basis PAMAM-Au labels, designed displayed excellent analytical performance with high sensitivity stability. This strategy successfully simple, cost-effective method, could be easily extended other protein analysis schemes.