Title
Assembly of multifunctionalized gold nanoparticles with chemiluminescent, catalytic and immune activity for label-free immunoassays
Author
Yao Huang, Lingfeng Gao, Hua Cui
Year
2018
Journal
ACS Applied Materials & Interfaces
Abstract
In this study, we report a universal label-free immunoassay to detect antigen based on multifunctionalized gold nanoparticles (MF-GNPs), which were obtained by successive assembly of N-aminobutyl-N-ethylisoluminol functionalized gold nanoparticles (ABEI-GNPs) with antibody, bovine serum albumin (BSA) and Co2+. MF-GNPs exhibited excellent chemiluminescent (CL), catalytic and immune activity. It was demonstrated that the CL signal of MF-GNPs decreased in the presence of antigens via antigen-antibody specific binding using human immunoglobulin G (hIgG) and corresponding antibody goat-anti-human IgG (anti-hIgG) as a model system, due to that immunoreaction led to the aggregation of GNPs. According to the decreased CL intensity, hIgG could be determined in the range of 1.0 fM to 1.0 nM with a low detection limit of 0.13 fM. Furthermore, this CL strategy was also confirmed to be a general one by replacing hIgG with heart-type fatty acid-binding protein (H-FABP), which is a biomarker of early Acute Myocardial infarction (AMI). The CL strategy could be employed to detect H-FABP ranging from 10.0 fM to 10.0 nM, and the detection limit is 7.8 fM. The CL strategy also showed good selectivity. It might be extended to detect other antigens if their corresponding antibodies are available.
Full Article
Instrument
J-1500
Keywords
Circular dichroism, Secondary structure, Nanostructures, Biochemistry, Materials