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Abdollah Salimi

Abdollah Salimi

Academic rank: Professor
ORCID:
Education: PhD.
ScopusId: 57198900488
Faculty: Faculty of Science
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Research

Title
A highly sensitive electrochemical immunosensor for hepatitis B virus surface antigen detection based on Hemin/G-quadruplex horseradish peroxidase-mimicking DNAzyme-signal amplification
Type
JournalPaper
Keywords
Electrochemical immunosensor Hemin/G-quadruplex Fe3O4 nanoparticle DNAzyme Hepatitis B virus surface antigen
Year
2017
Journal BIOSENSORS & BIOELECTRONICS
DOI
Researchers negar Alizadeh ، Rahman Hallaj ، Abdollah Salimi

Abstract

Here we prepared an electrochemical immunosensor employing Au sheet as working electrode, Fe3O4 magnetic nanoparticles (MNPs) as supporting matrix and hemin/G-quadruplex DNAzyme as signal amplifier for determination of hepatitis B virus surface antigen (HBsAg). First, the primary antibody of HBs (Ab1) was immobilized on the surface of the carboxyl-modified MNPs. Then, the assembly of antibody and alkylthiol/Gquadruplex DNA/hemin on gold nanoparticles was used as bio-bar-coded nanoparticle probe. Protein target was sandwiched between the primary antibody of HBs (Ab1) immobilized on the MNPs and hemin bio-barcoded AuNPs probe labeled antibody (Ab2). Hemin/G-quadruplex structure as HRP mimicking-DNAzyme significantly improved the catalytic reduction of H2O2 by oxidation of methylene blue (MB). Square wave voltammetry signals of MB provided quantitative measurements of HBsAg with a linear concentration range of 0.3–1000 pgmL−1 and detection limit of 0.19 pgmL−1. Due to efficient catalytic activity of HRP mimicking- DNAzyme, the proposed immunosensor exhibited high sensitivity and it holds great promise for clinical application and provides a new platform for immunosensor development and fast disease diagnosis.