Anodic‐Stripping Voltammetric Immunoassay for Ultrasensitive Detection of Low‐Abundance Proteins Using Quantum Dot Aggregated Hollow Microspheres
- 4 January 2013
- journal article
- research article
- Published by Wiley in Chemistry – A European Journal
- Vol. 19 (7), 2496-2503
- https://doi.org/10.1002/chem.201203131
Abstract
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 (Fc-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.This publication has 44 references indexed in Scilit:
- Water-Soluble Conjugated Polymers for Imaging, Diagnosis, and TherapyChemical Reviews, 2012
- DNA-Based Hybridization Chain Reaction for Amplified Bioelectronic Signal and Ultrasensitive Detection of ProteinsAnalytical Chemistry, 2012
- Sensing Technique of Silver Nanoparticles as Labels for Immunoassay Using Liquid Electrode Plasma Atomic Emission SpectrometryAnalytical Chemistry, 2012
- Screening of Several Drugs of Abuse in Italian Workplace Drug Testing: Performance Comparisons of On-Site Screening Tests and a Fluorescence Polarization Immunoassay-Based DeviceAnalytical Chemistry, 2011
- Comparative advantages of mechanical biosensorsNature Nanotechnology, 2011
- Highly Sensitive Immunoassay Based on Immunogold−Silver Amplification and Inductively Coupled Plasma Mass Spectrometric DetectionAnalytical Chemistry, 2011
- Phospholipid-Coated Carbon Nanotubes as Sensitive Electrochemical Labels with Controlled-Assembly-Mediated Signal Transduction for Magnetic Separation ImmunoassayAngewandte Chemie, 2009
- In Situ Amplified Electrochemical Immunoassay for Carcinoembryonic Antigen Using Horseradish Peroxidase-Encapsulated Nanogold Hollow Microspheres as LabelsAnalytical Chemistry, 2008
- Spontaneous Formation and Electrogenerated Chemiluminescence of Tris(bipyridine) Ru(II) Derivative NanobeltsJournal of the American Chemical Society, 2008
- Ultrasensitive Electrochemical Immunosensor for Clinical Immunoassay Using Thionine-Doped Magnetic Gold Nanospheres as Labels and Horseradish Peroxidase as EnhancerAnalytical Chemistry, 2008