Ultrasensitive fluorescent detection of telomerase activity based on tetrahedral DNA nanostructures as carriers for DNA-templated silver nanoclusters

Anal Bioanal Chem. 2022 Mar;414(7):2431-2438. doi: 10.1007/s00216-022-03883-1. Epub 2022 Jan 17.

Abstract

Precise evaluation of telomerase activity is essential for the clinical diagnosis of early tumors. Herein, we have ingeniously designed a tetrahedral DNA nanostructure, with hairpin-shaped DNA probes rich in cytosine bases at four vertices for telomerase detection. The DNA-templated silver nanoclusters can be formed after the addition of Ag. Then the introduction of telomerase adds the single-strand TTAGGG extension, which can "turn on" the fluorescence of silver nanoclusters quickly by the proximity of the resulting guanine-rich sequences to silver nanoclusters and realize accurate detection of telomerase activity. In this study, integration of high stability tetrahedral DNA nanostructure and fluorescence signal amplification of four DNA-templated silver nanoclusters offers the advantage of high sensitivity, with a low detection limit of 1 cell. More than that, this method is low-cost, facile, and feasible for practical clinical applications.

Keywords: AgNC; Fluorescence; Telomerase; Tetrahedral DNA.

MeSH terms

  • Biosensing Techniques* / methods
  • DNA / chemistry
  • Fluorescence
  • Fluorescent Dyes / chemistry
  • Metal Nanoparticles* / chemistry
  • Nanostructures* / chemistry
  • Silver / chemistry
  • Spectrometry, Fluorescence
  • Telomerase*

Substances

  • Fluorescent Dyes
  • Silver
  • DNA
  • Telomerase