Ultrasensitive Electrochemiluminescence Imaging Detection of Multiple miRNAs in Single Cells with a Closed Bipolar Electrode Array Chip

Anal Chem. 2024 Jul 23;96(29):12112-12119. doi: 10.1021/acs.analchem.4c02186. Epub 2024 Jul 11.

Abstract

In situ sensitive detection of multiple biomarkers in a single cell was highly necessary for understanding the pathogenesis mechanism and facilitating disease diagnosis. Herein, a bipolar electrode (BPE)-electrochemiluminescence (ECL) imaging chip was designed for ultrasensitive in situ detection of multiple miRNAs in single cells based on a dual-signal amplification strategy. A single cell was trapped and lysed within the microtrap of the cathode chamber and an HCR amplification process and nanoprobes (Fc/DNA/Fe3O4) were introduced, leading to a large number of electroactive molecules (Fc) being modified on the surface. Under a suitable potential, Fc+ in the cathodic chamber was reduced to Fc and L-012 was oxidized in the anodic chamber according to the electric neutrality principle of the bipolar electrode system, resulting in the ECL signal recorded by EMCCD. Ascribed to the dual-signal amplification, sensitive visual detection of miRNA-21 and miRNA-155 in single cells was achieved. For MCF-7 cells, miRNA-21 and miRNA-155 were calculated to be 4385 and 1932 copies/cell (median), respectively. For HeLa cells, miRNA-21 and miRNA-155 were calculated to be 1843 and 1012 copies/cell (median), respectively. The comprehensive evaluation of two kinds of miRNA could effectively eliminate error signals, and the detection precision was improved by 10%.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Electrochemical Techniques*
  • Electrodes*
  • HeLa Cells
  • Humans
  • Limit of Detection
  • Luminescent Measurements*
  • MCF-7 Cells
  • MicroRNAs* / analysis
  • Single-Cell Analysis*

Substances

  • MicroRNAs
  • MIRN155 microRNA, human
  • MIRN21 microRNA, human