Gold-based optical biosensor for single-mismatched DNA detection using salt-induced hybridization

Zongrui Zhan, Xingyi Ma, Cuong Cao, Sang Jun Sim

Research output: Contribution to journalArticlepeer-review

27 Citations (Scopus)


In this study, a gold nanoparticle (Au-NP)-based detection method for sensitive and specific DNA-based diagnostic applications is described. A sandwich format consisting of Au-NPs/DNA/PMP (Streptavidin-coated MagnetSphere Para-Magnetic Particles) was fabricated. PMPs captured and separated target DNA while Au-NPs modified with oligonucleotide detection sequences played a role in recognition and signal production. Due to the much lower stability of mismatched DNA strands caused by unstable duplex structures in solutions of relatively low salt concentration, hybridization efficiency in the presence of different buffers was well investigated, and thus, the optimized salt concentration allowed for discrimination of single-mismatched DNA (MMT) from perfectly matched DNA (PMT). Therefore, quantitative information concerning the target analyte was translated into a colorimetric signal, which could easily and quantitatively measured by low-cost UV-vis spectrophotometric analysis. The results indicated this to be a very simple and economic strategy for detection of single-mismatched DNA strands.

Original languageEnglish
Pages (from-to)127-132
Number of pages6
JournalBiosensors and Bioelectronics
Issue number1
Publication statusPublished - 2012 Feb 15


  • BRCA-1
  • DNA hybridization
  • Gold nanoparticles
  • Salt-induced
  • Single-mismatched detection

ASJC Scopus subject areas

  • Biotechnology
  • Biophysics
  • Biomedical Engineering
  • Electrochemistry


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