A novel ultrasensitive ECL sensor for DNA detection based on nicking endonuclease-assisted target recycling amplification, rolling circle amplification and hemin/G-quadruplex

Sensors (Basel). 2015 Jan 26;15(2):2629-43. doi: 10.3390/s150202629.

Abstract

In this study, we describe a novel universal and highly sensitive strategy for the electrochemiluminescent (ECL) detection of sequence specific DNA at the aM level based on Nt.BbvCI (a nicking endonuclease)-assisted target recycling amplification (TRA), rolling circle amplification (RCA) and hemin/G-quadruplex. The target DNAs can hybridize with self-assembled capture probes and assistant probes to form "Y" junction structures on the electrode surface, thus triggering the execution of a TRA reaction with the aid of Nt.BbvCI. Then, the RCA reaction and the addition of hemin result in the production of numerous hemin/G-quadruplex, which consume the dissolved oxygen in the detection buffer and result in a significant ECL quenching effect toward the O2/S2O8(2-) system. The proposed strategy combines the amplification ability of TRA, RCA and the inherent high sensitivity of the ECL technique, thus enabling low aM (3.8 aM) detection for sequence-specific DNA and a wide linear range from 10.0 aM to 1.0 pM. At the same time, this novel strategy shows high selectivity against single-base mismatch sequences, which makes our novel universal and highly sensitive method a powerful addition to specific DNA sequence detection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biosensing Techniques*
  • DNA / chemistry
  • DNA / isolation & purification*
  • DNA Replication / genetics
  • Electrochemical Techniques
  • Endonucleases / chemistry
  • Endonucleases / genetics*
  • G-Quadruplexes
  • Hemin / chemistry
  • Hemin / genetics

Substances

  • Hemin
  • DNA
  • Endonucleases