TY - JOUR
T1 - Anodic-stripping voltammetric immunoassay for ultrasensitive detection of low-abundance proteins using quantum dot aggregated hollow microspheres
AU - Zhang, Bing
AU - Tang, Dianping
AU - Goryacheva, Irina Yu
AU - Niessner, Reinhard
AU - Knopp, Dietmar
PY - 2013/2/11
Y1 - 2013/2/11
N2 - A new anodic-stripping voltammetric immunoassay protocol for detection of IgG1, as a model protein, was designed by using CdS quantum dot (QD) layer-by-layer assembled hollow microspheres (QDHMS) as molecular tags. Initially, monoclonal anti-human IgG1 specific antibodies were anchored on amorphous magnetic beads preferably selective to capture Fab of IgG1 analyte from the sample. For detection, monoclonal anti-human IgG1 (F c-specific) antibodies were covalently coupled to the synthesized QDHMS. In a sandwich-type immunoassay format, subsequent anodic-stripping voltammetric detection of cadmium released under acidic conditions from the coupled QDs was conducted at an in situ prepared mercury film electrode. The immunoassay combines highly efficient magnetic separation with signal amplification by the multilayered QD labels. The dynamic concentration range spanned from 1.0 fg mL-1 to 1.0 μg mL-1 of IgG1 with a detection limit of 0.1 fg mL-1. The electrochemical immunoassay showed good reproducibility, selectivity, and stability. The analysis of clinical serum specimens revealed good accordance with the results obtained by an enzyme-linked immunosorbent assay method. The new immunoassay is promising for enzyme-free, and cost-effective analysis of low-abundance biomarkers. A sandwich-type immunoassay for ultrasensitive detection of low-abundance proteins was developed by using mAb2-functionalized quantum dot aggregated hollow microspheres (QDHMS), as tags on an mAb1-functionalized magnetic-bead (MB)-based platform. In the immunoassay, square-wave anodic-stripping voltammetric (SWASV) detection of Cd released under acidic conditions from the coupled QDs was conducted.
AB - A new anodic-stripping voltammetric immunoassay protocol for detection of IgG1, as a model protein, was designed by using CdS quantum dot (QD) layer-by-layer assembled hollow microspheres (QDHMS) as molecular tags. Initially, monoclonal anti-human IgG1 specific antibodies were anchored on amorphous magnetic beads preferably selective to capture Fab of IgG1 analyte from the sample. For detection, monoclonal anti-human IgG1 (F c-specific) antibodies were covalently coupled to the synthesized QDHMS. In a sandwich-type immunoassay format, subsequent anodic-stripping voltammetric detection of cadmium released under acidic conditions from the coupled QDs was conducted at an in situ prepared mercury film electrode. The immunoassay combines highly efficient magnetic separation with signal amplification by the multilayered QD labels. The dynamic concentration range spanned from 1.0 fg mL-1 to 1.0 μg mL-1 of IgG1 with a detection limit of 0.1 fg mL-1. The electrochemical immunoassay showed good reproducibility, selectivity, and stability. The analysis of clinical serum specimens revealed good accordance with the results obtained by an enzyme-linked immunosorbent assay method. The new immunoassay is promising for enzyme-free, and cost-effective analysis of low-abundance biomarkers. A sandwich-type immunoassay for ultrasensitive detection of low-abundance proteins was developed by using mAb2-functionalized quantum dot aggregated hollow microspheres (QDHMS), as tags on an mAb1-functionalized magnetic-bead (MB)-based platform. In the immunoassay, square-wave anodic-stripping voltammetric (SWASV) detection of Cd released under acidic conditions from the coupled QDs was conducted.
KW - analytical methods
KW - immunoassays
KW - proteins
KW - quantum dots
KW - voltammetry
UR - http://www.scopus.com/inward/record.url?scp=84873342755&partnerID=8YFLogxK
U2 - 10.1002/chem.201203131
DO - 10.1002/chem.201203131
M3 - Article
C2 - 23292875
AN - SCOPUS:84873342755
SN - 0947-6539
VL - 19
SP - 2496
EP - 2503
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
IS - 7
ER -