Abstract
Glass-based microchannel chips were fabricated using photolithographic technology, and Pt thin-film microelectrodes as dielectric biosensors were integrated on them. From capacitance-frequency measurements at various interelectrode distances and ionic concentrations, a significant difference between deionized (DI) water and tris-ethylenediaminetetraacetic acid (EDTA) (TE) buffer was observed in the low-frequency region. Although the capacitance (CM) of the DI water decreased as the interelectrode distance increased, that of the TE buffer was similar up to a frequency of 100 Hz, after which it was spilt in the same manner as the DI water above 100 Hz. As the ionic concentration increased, the CM of the TE buffer increased and the slope in the low frequency region changed from -0.875 to -0.425. The point where the slope changed shifted towards the frequency increase. These observations were clarified from the viewpoint of interfacial phenomena, such as the electrical double layer and Faradaic reactions, the dielectric constant related to conductivity, and the capacitance inversely proportional to the interelectrode distance. The addition of deoxyribonucleic acid (DNA) molecules (10ng/ul) increased the capacitance and dielectric loss in the TE buffer at low frequency. It is feasible to use dielectric properties for the rapid and direct detection of biomolecules, particularly DNA molecules, without using labels or indicators.
| Original language | English |
|---|---|
| Pages (from-to) | 5639-5645 |
| Number of pages | 7 |
| Journal | Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers |
| Volume | 43 |
| Issue number | 8 A |
| DOIs | |
| Publication status | Published - 2004 Aug 1 |
| Externally published | Yes |
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Keywords
- Capacitance
- Dielectric biosensor
- Dielectric loss
- DNA detection
- Electrical double layer
ASJC Scopus subject areas
- Engineering(all)
- Physics and Astronomy(all)
Cite this
A dielectric biosensor using the capacitance change with AC frequency integrated on glass substrates. / Hong, Jongin; Yoon, Dae Sung; Park, Myung Il; Choi, Jongwan; Kim, Tae Song; Im, Geunbae; Kim, Sanghyo; Eugene Pak, Y.; No, Kwangsoo.
In: Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers, Vol. 43, No. 8 A, 01.08.2004, p. 5639-5645.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - A dielectric biosensor using the capacitance change with AC frequency integrated on glass substrates
AU - Hong, Jongin
AU - Yoon, Dae Sung
AU - Park, Myung Il
AU - Choi, Jongwan
AU - Kim, Tae Song
AU - Im, Geunbae
AU - Kim, Sanghyo
AU - Eugene Pak, Y.
AU - No, Kwangsoo
PY - 2004/8/1
Y1 - 2004/8/1
N2 - Glass-based microchannel chips were fabricated using photolithographic technology, and Pt thin-film microelectrodes as dielectric biosensors were integrated on them. From capacitance-frequency measurements at various interelectrode distances and ionic concentrations, a significant difference between deionized (DI) water and tris-ethylenediaminetetraacetic acid (EDTA) (TE) buffer was observed in the low-frequency region. Although the capacitance (CM) of the DI water decreased as the interelectrode distance increased, that of the TE buffer was similar up to a frequency of 100 Hz, after which it was spilt in the same manner as the DI water above 100 Hz. As the ionic concentration increased, the CM of the TE buffer increased and the slope in the low frequency region changed from -0.875 to -0.425. The point where the slope changed shifted towards the frequency increase. These observations were clarified from the viewpoint of interfacial phenomena, such as the electrical double layer and Faradaic reactions, the dielectric constant related to conductivity, and the capacitance inversely proportional to the interelectrode distance. The addition of deoxyribonucleic acid (DNA) molecules (10ng/ul) increased the capacitance and dielectric loss in the TE buffer at low frequency. It is feasible to use dielectric properties for the rapid and direct detection of biomolecules, particularly DNA molecules, without using labels or indicators.
AB - Glass-based microchannel chips were fabricated using photolithographic technology, and Pt thin-film microelectrodes as dielectric biosensors were integrated on them. From capacitance-frequency measurements at various interelectrode distances and ionic concentrations, a significant difference between deionized (DI) water and tris-ethylenediaminetetraacetic acid (EDTA) (TE) buffer was observed in the low-frequency region. Although the capacitance (CM) of the DI water decreased as the interelectrode distance increased, that of the TE buffer was similar up to a frequency of 100 Hz, after which it was spilt in the same manner as the DI water above 100 Hz. As the ionic concentration increased, the CM of the TE buffer increased and the slope in the low frequency region changed from -0.875 to -0.425. The point where the slope changed shifted towards the frequency increase. These observations were clarified from the viewpoint of interfacial phenomena, such as the electrical double layer and Faradaic reactions, the dielectric constant related to conductivity, and the capacitance inversely proportional to the interelectrode distance. The addition of deoxyribonucleic acid (DNA) molecules (10ng/ul) increased the capacitance and dielectric loss in the TE buffer at low frequency. It is feasible to use dielectric properties for the rapid and direct detection of biomolecules, particularly DNA molecules, without using labels or indicators.
KW - Capacitance
KW - Dielectric biosensor
KW - Dielectric loss
KW - DNA detection
KW - Electrical double layer
UR - http://www.scopus.com/inward/record.url?scp=6344229748&partnerID=8YFLogxK
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U2 - 10.1143/JJAP.43.5639
DO - 10.1143/JJAP.43.5639
M3 - Article
VL - 43
SP - 5639
EP - 5645
JO - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
JF - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
SN - 0021-4922
IS - 8 A
ER -