A highly sensitive electrochemical biosensor for protein based on a tetrahedral DNA probe, N- and P-co-doped graphene, and rolling circle amplification

Anal Bioanal Chem. 2020 Feb;412(4):915-922. doi: 10.1007/s00216-019-02314-y. Epub 2020 Jan 3.

Abstract

A tetrahedral DNA probe can effectively overcome the steric effects of a single-stranded probe to obtain well-controlled density and minimize nonspecific adsorption. Herein, a highly sensitive electrochemical biosensor is fabricated for determination of protein using a tetrahedral DNA probe and rolling circle amplification (RCA). N- and P-co-doped graphene (NP-rGO) is prepared, and AuNPs are then electrodeposited on it for DNA probe immobilization. Benefitting from the synergistic effects of the excellent electrical conductivity of NP-rGO, the stability of the tetrahedral DNA probe and the signal amplification of RCA, the biosensor achieves a low limit of 3.53 × 10-14 M for thrombin and a wide linear range from 1 × 10-13 to 1 × 10-7 M. This study provides a sensitive and effective method for the detection of protein in peripheral biofluids, and paves the way for future clinical diagnostics and treatment of disease. Graphical abstract.

Keywords: N- and P-Co-doped graphene; Protein; Rolling circle amplification; Sensitive determination; Tetrahedral DNA probe.

Publication types

  • Evaluation Study

MeSH terms

  • Aptamers, Nucleotide / chemistry*
  • Biosensing Techniques / methods*
  • DNA Probes / chemistry
  • Electrochemical Techniques / methods
  • Gold / chemistry
  • Graphite / chemistry*
  • Humans
  • Immobilized Nucleic Acids / chemistry
  • Limit of Detection
  • Metal Nanoparticles / chemistry
  • Nucleic Acid Amplification Techniques / methods
  • Thrombin / analysis*

Substances

  • Aptamers, Nucleotide
  • DNA Probes
  • Immobilized Nucleic Acids
  • Gold
  • Graphite
  • Thrombin