Abstract
In this study, a novel dual-modal electrochemical impedance spectroscopy (EIS) and electrochemiluminescence (ECL) biosensor for sensitive detection of femtomolar miRNA-126 was developed based on hybridization chain reaction (HCR). The capture unit was Fe3O4@SiO2@AuNPs-cDNA, being Fe3O4@SiO2@AuNPs nanoparticles coated by hairpin cDNA which could capture miRNA-126 specifically. The signal unit was HCR-Ru(phen)3
2+, which was a long double-stranded DNA obtained through HCR with a great number of ECL signal labels Ru(phen)3
2+ embedded. In presence of target miRNA-126, stem-loop structure of cDNA in the capture unit was opened and a partial dsDNA was formed, the residue bases of which hybridized with the signal unit to form a capture unit/miRNA-126/signal unit complex on the electrode surface. In this case, dual-modal biosensor was prepared easily by the help of magnet, and EIS and ECL detection was both acquired. In addition, a miRNA-126 molecule corresponded to a long double-stranded DNA and a large amount of Ru(phen)3
2+ ions embedded, so the electrochemical impedance and the ECL intensity were greatly increased, with a limit of detection (LOD) of 2 fM. And, EIS and ECL results could be checked mutually, improving the detection accuracy and reliability. It offers a simple, fast, sensitive, selective and accurate approach for versatile analysis of microRNAs.
Funder
National Natural Science Foundation of China
Publisher
The Electrochemical Society
Subject
Materials Chemistry,Electrochemistry,Surfaces, Coatings and Films,Condensed Matter Physics,Renewable Energy, Sustainability and the Environment,Electronic, Optical and Magnetic Materials
Cited by
10 articles.
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