A label-free fluorescent biosensor based on a catalyzed hairpin assembly for HIV DNA and lead detection

Anal Methods. 2021 Jun 7;13(21):2391-2395. doi: 10.1039/d1ay00410g. Epub 2021 May 11.


Herein, a label-free fluorescent signal amplification system based on a catalyzed hairpin assembly (CHA) is reported. In this system, two hairpin probes, H1 and H2, were well-designed in which G-quadruplex sequences were integrated into H2. The CHA reaction was triggered by target/trigger DNA and G-quadruplex sequences were released, which can bind the fluorescent amyloid dye thioflavin T (ThT) to provide fluorescence signals. At the same time, target/trigger DNA was released from the product of the CHA reaction (H1-H2), which continued to initiate the next CHA cycle, and the signal was eventually amplified. This signal amplification approach has been successfully used to develop a label-free fluorescent sensing platform for sensitive detection of human immunodeficiency virus (HIV) DNA and Pb2+.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biosensing Techniques*
  • Catalysis
  • DNA
  • G-Quadruplexes*
  • Humans
  • Limit of Detection


  • DNA