Label-free and Electrochemical Detection of Nucleic Acids Based on Isothermal Amplification in Combination with Solid-state pH Sensor

Miyuki Tabata, Yurika Katayama, Fahmida Mannan, Ayaka Seichi, Koji Suzuki, Tatsuro Goda, Akira Matsumoto, Yuji Miyahara

Research output: Contribution to journalArticle

5 Citations (Scopus)


Label-free quantification methods for nucleic acids are attracting attention, since they provide potential tools in clinical applications such as disease diagnosis or prognosis observation. In this research, we developed a simpler and cost-effective electrical monitoring device of nucleic acid amplification, combining an isothermal amplification method and an Iridium/Iridium oxide (Ir/IrOx) electrode without labeling. The fabricated Ir/IrOx electrode showed ideal Nernstian response under the various pH buffer solutions, and its potential response was less affected even in the presence of charged proteins. Moreover, we successfully real-time monitored primer generation-rolling circle amplification (PG-RCA) at the 0, 10, 100, 1000 pM of target DNA by detection of released proton during amplification reaction at the constant reaction temperature. This label-free and portable device might be received considerable attention as a useful platform for a point-of-care testing in clinical use.

Original languageEnglish
Pages (from-to)419-422
Number of pages4
JournalProcedia Engineering
Publication statusPublished - 2016



  • Biosensor
  • iridium/iridium oxide
  • isothermal nucleic acid amplification

ASJC Scopus subject areas

  • Engineering(all)

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