Target switching catalytic hairpin assembly and gold nanoparticle colorimetric for EGFR mutant detection

Chanho Park, Youngjin Song, Kuewhan Jang, Chang Hwan Choi, Sungsoo Na

Research output: Contribution to journalArticlepeer-review

32 Citations (Scopus)


The detection of circulating tumor DNAs (ctDNAs) with high sensitivity plays an important role in liquid biopsy diagnosis. For the detection of ctDNAs, we investigated the applicability of a two-ways CHA technique and found there were several problems such as sensitivity and selectivity. For this reason, we revised our technique to three-ways target switching catalytic hairpin assembly (TSCHA). Our target DNA is epidermal growth factor receptor (EGFR) mutation DNA. EGFR mutation DNA is very long DNA (84 mer) and it is hard to detect such a long DNA. However, with a TSCHA method, we can produce a short catalyst DNA (c-DNA) using long target DNA. After the catalytic reaction between DNAs, AuNPs aggregate and the detection solution become blue from red. We quantify the aggregation by observing UV–vis spectrum and can obtain LOD as low as 7.7 fM. Also the selectivity of the detection method is very high. Because of the high sensitivity, high selectivity, and simplicity, the TSCHA technique has great potential as a platform to detect mutant DNA in blood of cancer patients.

Original languageEnglish
Pages (from-to)497-504
Number of pages8
JournalSensors and Actuators, B: Chemical
Publication statusPublished - 2018 May 15

Bibliographical note

Publisher Copyright:
© 2018 Elsevier B.V.


  • Catalytic hairpin assembly
  • Circulation tumor DNA
  • Colorimetric
  • DNA detection
  • High sensitivity

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Instrumentation
  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Electrical and Electronic Engineering
  • Materials Chemistry


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