Jump to main content
Jump to site search


MicroRNA Detection of Amplification-Free Based on Controllable Solid-State Electrochemiluminescence Quenched by Charge Transfer

Abstract

Abstract Effective and sensitive microRNA detection is a great challenge. Most of microRNA assays applied amplification strategy to obtain high sensitivity, which made them complicated. Herein, we present a simple and amplification-free solid-state electrochemiluminescence (ECL) biosensor for the detection of miRNA based on high effective quenching by ferrocene and using N-butyldiethanolamine (BDEA) as a more effective co-reactant. Initially, the mixture of Nafion and Au nanoparticles (AuNPs) was cast onto the glassy carbon electrode (GCE) to form a Nafion-AuNPs film. The resulted electrode was then immersed into a solution of Ru(bpy)32+, where the solid-state Nafion-AuNPs/Ru(bpy)32+ could be obtained via electrostatic adsorption. The DNA molecular beacon, which was modified with thiol at one distal and the other was labeled with ferrocene (i.e., Fc-MB), was covalently attached to AuNPs on ECL film through Au-S bond. Afterwards, the remaining active sites of nonspecific adsorption were blocked with 6-mercapto-1-hexanol (MCH). When target miRNA was present, it hybridized with the complementary part in the loop of Fc-MB and formed a double-stranded structure. This conformational change led the quencher away from the electrode, resulting in a remarkable increase of ECL intensity. Under the optimum condition, ECL signal had a linear relationship with miRNA concentration ranging from 0.01 pM to 1 × 103 pM,with a limit of detection of 10 fM. Moreover, our biosensor showed remarkable specificity, outstanding reproducibility, good stability and excellent performance in real sample investigation with no amplification. Therefore, this developed strategy has great potential in early miRNA-related cancer diagnosis.

Back to tab navigation

Publication details

The article was received on 18 Jul 2017, accepted on 22 Sep 2017 and first published on 22 Sep 2017


Article type: Paper
DOI: 10.1039/C7AY01724C
Citation: Anal. Methods, 2017, Accepted Manuscript
  •   Request permissions

    MicroRNA Detection of Amplification-Free Based on Controllable Solid-State Electrochemiluminescence Quenched by Charge Transfer

    L. Lu, C. Liu, T. Kang and L. Wang, Anal. Methods, 2017, Accepted Manuscript , DOI: 10.1039/C7AY01724C

Search articles by author

Spotlight

Advertisements