Fabrication of a multi-electrode array DNA sensor form electrochemical genotyping

Sungbo Cho, James Jungho Pak, Jinseop Hong, Youngmi KimPak

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)


One of the essential conditions of genotyping is a high precision in detection such as that required in gene diagnosis to detect genetic lesions and mutations. Using a fabricated multi-electrode array (4 by 4) DNA sensor, we were able to distinguish perfectly matched double-stranded DNAs from both single-stranded DNAs and single-base mismatched DNA double strands. Au was used the electrode material, and a photoresist (AZ1512) was used as an insulating layer. 2-mercaptoethanol was used as the self-assembled monolayer for linking the DNA to the Au electrode, and methylene blue (MB) was used as an indicator that could be selectively bound to double-stranded DNA. Using cyclic voltammetry to measure the redox reaction of methylene blue, we observed the reductive peak current of methylene blue when the input voltage of cyclic voltammetry was -260 mV at the working electrode (vs. Ag/AgCl). The measured current of perfectly matched double-stranded DNA was 590 nA at this potential. This value was larger than that of the single-base mismatched DNA double strand (340 nA). Thus, normal double-stranded DNA can be distinguished from a single-base mismatched DNA through an analysis of reductive peak current of methylene blue. This result makes possible a precise electrochemical genotyping using this multi-electrode array DNA sensor which can detect a single-base mismatched DNA double strand in just a few seconds.

Original languageEnglish
Pages (from-to)1054-1057
Number of pages4
JournalJournal of the Korean Physical Society
Issue number6
Publication statusPublished - 2002 Dec


  • 1-base mismatched DNA erection
  • Cyclic voltametry
  • Electrochemical detection
  • Thin film

ASJC Scopus subject areas

  • Physics and Astronomy(all)


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