A novel electrochemical biosensor for ultrasensitive and specific detection of DNA based on molecular beacon mediated circular strand displacement and rolling circle amplification

Biosens Bioelectron. 2014 Dec 15:62:274-9. doi: 10.1016/j.bios.2014.06.056. Epub 2014 Jul 1.

Abstract

A novel electrochemical biosensing strategy was developed for ultrasensitive and specific detection of target DNA using a cascade signal amplification based on molecular beacon (MB) mediated circular strand displacement (CSD), rolling circle amplification (RCA), biotin-strepavidin system, and enzymatic amplification. The target DNA hybridized with the loop portion of MB probe immobilized on the gold electrode and triggered the CSD, leading to multiple biotin-tagged DNA duplex. Furthermore, via biotin-streptavidin interaction, the RCA was implemented, producing long massive tandem-repeat DNA sequences for binding numerous biotinylated detection probes. This enabled an ultrasensitive electrochemical readout by further employing the streptavidin-alkaline phosphatase. The proposed biosensor showed very high sensitivity and selectivity with a dynamic response range from 1 fM to 100 pM. The proposed strategy could have the potential for applying in clinical molecular diagnostics and environmental monitoring.

Keywords: Alkaline phosphatase; Circular isothermal strand displacement amplification; Electrochemical DNA sensor; Rolling circle amplification.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biosensing Techniques / instrumentation
  • Biosensing Techniques / methods*
  • Biosensing Techniques / statistics & numerical data
  • Biotin
  • DNA / analysis*
  • DNA / genetics
  • Dielectric Spectroscopy
  • Electrochemical Techniques
  • Environmental Monitoring
  • Humans
  • Molecular Diagnostic Techniques
  • Nucleic Acid Amplification Techniques
  • Nucleic Acid Hybridization
  • Reproducibility of Results
  • Streptavidin

Substances

  • Biotin
  • DNA
  • Streptavidin