DNA probe functionalized QCM biosensor based on gold nanoparticle amplification for Bacillus anthracis detection

Biosens Bioelectron. 2011 Apr 15;26(8):3398-404. doi: 10.1016/j.bios.2011.01.010. Epub 2011 Jan 13.


The rapid detection of Bacillus anthracis, the causative agent of anthrax disease, has gained much attention since the anthrax spore bioterrorism attacks in the United States in 2001. In this work, a DNA probe functionalized quartz crystal microbalance (QCM) biosensor was developed to detect B. anthracis based on the recognition of its specific DNA sequences, i.e., the 168 bp fragment of the Ba813 gene in chromosomes and the 340 bp fragment of the pag gene in plasmid pXO1. A thiol DNA probe was immobilized onto the QCM gold surface through self-assembly via Au-S bond formation to hybridize with the target ss-DNA sequence obtained by asymmetric PCR. Hybridization between the target DNA and the DNA probe resulted in an increase in mass and a decrease in the resonance frequency of the QCM biosensor. Moreover, to amplify the signal, a thiol-DNA fragment complementary to the other end of the target DNA was functionalized with gold nanoparticles. The results indicate that the DNA probe functionalized QCM biosensor could specifically recognize the target DNA fragment of B. anthracis from that of its closest species, such as Bacillus thuringiensis, and that the limit of detection (LOD) reached 3.5 × 10(2)CFU/ml of B. anthracis vegetative cells just after asymmetric PCR amplification, but without culture enrichment. The DNA probe functionalized QCM biosensor demonstrated stable, pollution-free, real-time sensing, and could find application in the rapid detection of B. anthracis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacillus anthracis / genetics
  • Bacillus anthracis / isolation & purification*
  • Biosensing Techniques / methods*
  • DNA Probes*
  • Gold / chemistry*
  • Limit of Detection
  • Metal Nanoparticles / chemistry*
  • Plasmids
  • Quartz Crystal Microbalance Techniques / methods*


  • DNA Probes
  • Gold