Label-free DNA sensors using ultrasensitive diamond field-effect transistors in solution

Kwang Soup Song, Gou Jun Zhang, Yusuke Nakamura, Kei Furukawa, Takahiro Hiraki, Jung Hoon Yang, Takashi Funatsu, Iwao Ohdomari, Hiroshi Kawarada

Research output: Contribution to journalArticlepeer-review

80 Citations (Scopus)

Abstract

Charge detection biosensors have recently become the focal point of biosensor research, especially field-effect-transistors (FETs) that combine compactness, low cost, high input, and low output impedances, to realize simple and stable in vivo diagnostic systems. However, critical evaluation of the possibility and limitations of charge detection of label-free DNA hybridization using silicon-based ion-sensitive FETs (ISFETs) has been introduced recently. The channel surface of these devices must be covered by relatively thick insulating layers (Si O2, Si3 N4, Al2 O3, or Ta2 O5) to protect against the invasion of ions from solution. These thick insulating layers are not suitable for charge detection of DNA and miniaturization, as the small capacitance of thick insulating layers restricts translation of the negative DNA charge from the electrolyte to the channel surface. To overcome these difficulties, thin-gate-insulator FET sensors should be developed. Here, we report diamond solution-gate FETs (SGFETs), where the DNA-immobilized channels are exposed directly to the electrolyte solution without gate insulator. These SGFETs operate stably within the large potential window of diamond (>3.0 V). Thus, the channel surface does not need to be covered by thick insulating layers, and DNA is immobilized directly through amine sites, which is a factor of 30 more sensitive than existing Si-ISFET DNA sensors. Diamond SGFETs can rapidly detect complementary, 3-mer mismatched (10 pM) and has a potential for the detection of single-base mismatched oligonucleotide DNA, without biological degradation by cyclically repeated hybridization and denature.

Original languageEnglish
Article number041919
JournalPhysical Review E - Statistical, Nonlinear, and Soft Matter Physics
Volume74
Issue number4
DOIs
Publication statusPublished - 2006 Nov 6

ASJC Scopus subject areas

  • Statistical and Nonlinear Physics
  • Statistics and Probability
  • Condensed Matter Physics

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