Novel dielectric-modulated field-effect transistor for label-free DNA detection

Chang Hoon Kim, Cheulhee Jung, Hyun Gyu Park, Yang Kyu Choi

Research output: Contribution to journalArticle

59 Citations (Scopus)

Abstract

This paper describes two competing factors, a dielectric constant and a charge in a dielectric-modulated field-effect transistor (DMFET), for label-free DNA electrical detection. Essentially, the DMFET electrically detects biomolecules by monitoring a change of threshold voltage caused by a change of dielectric constant when targeted biomolecules are confined to a nanogap of the DMFET. In particular, when charged biomolecules such as DNA are introduced into the nanogap, the DMFET operation can be changed by both the dielectric constant and the strength of the charges in the gate dielectric layer. In this work, negatively-charged DNA and neutralized DNA by sodium ion treatment are carefully compared using an n-channel DMFET in order to verify the contribution to a change of threshold voltage by the DNA charges. In the case of neutralized DNA, the threshold voltage is shifted to the negative side as previously reported. However, in the case of negatively-charged DNA, the threshold voltage is shifted to the positive side due to the negative charges of this DNA. Hence, a p-channel DMFET is clearly preferable in detections of negatively-charged DNA.

Original languageEnglish
Pages (from-to)127-134
Number of pages8
JournalBiochip Journal
Volume2
Issue number2
Publication statusPublished - 2009 Jan 1

Keywords

  • Charge effect
  • DMFET
  • DNA
  • Dielectric constant effect
  • Label-free electrical detection
  • Nanogap

ASJC Scopus subject areas

  • Biotechnology
  • Bioengineering
  • Biomedical Engineering
  • Electrical and Electronic Engineering

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