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Nanogap Capacitors for Label Free DNA Analysis

Published online by Cambridge University Press:  01 February 2011

Joon Sung Lee
Affiliation:
Berkeley Sensor and Actuator Center Department of Bioengineering, University of California at Berkeley, Berkeley, CA 94720
Yang-Kyu Choi
Affiliation:
Berkeley Sensor and Actuator Center Department of Bioengineering, University of California at Berkeley, Berkeley, CA 94720
Michael Pio
Affiliation:
Berkeley Sensor and Actuator Center Department of Bioengineering, University of California at Berkeley, Berkeley, CA 94720
Jeonggi Seo
Affiliation:
Berkeley Sensor and Actuator Center Department of Bioengineering, University of California at Berkeley, Berkeley, CA 94720
Luke P. Lee
Affiliation:
Berkeley Sensor and Actuator Center Department of Bioengineering, University of California at Berkeley, Berkeley, CA 94720
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Abstract

Nanogap capacitors are fabricated for DNA hybridization detection. Without labeling, the nanogap capacitors on a chip can function as DNA microarray sensors. The difference in dielectric properties between single-stranded DNA and double-stranded DNA permits use of capacitance measurements to detect hybridization. To obtain high detection sensitivity, a 50 nm gap capacitor was fabricated using a Si-nanotechnology. To ensure proper measurement of DNA's dielectrical properties, the probe ssDNA was first immobilized onto the electrode surface using self-assembly monolayers and allowed to hybridize with the target ssDNA. The capacitance changes were measured for 35-mer homonucleotides. The self-assembly monolayer and DNA immobilization events were verified independently by contact angle measurement and FTIR. Capacitance values are measured at frequencies ranging from 75 kHz to 5 MHz, using 0 VDC bias and 25 mVAC signals. Approximately 9% change in capacitance was observed after DNA hybridization at 75 kHz.

Type
Research Article
Copyright
Copyright © Materials Research Society 2002

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References

[1] Marrazza, G., Chianella, I., Mascini, M., Biosensors and Bioelectronics 14, 43 (1999)Google Scholar
[2] Palecek, E., Fojta, M., Tomschik, M., Wang, J., Biosensors and Bioelectronics 13, 621 (1998)Google Scholar
[3] Piunno, P.A.E., Krull, U.J., Hudson, R.H.E., Damah, M.J., Cohen, H., Analytica Chimica Acta 288, 205 (1994)Google Scholar
[4] Berney, H., West, J., Haefele, E., Alderman, J., Lane, W. and Collins, J.K., Sensors and Actuators B 68, 100 (2000)Google Scholar
[5] Berggren, C., Stalhandske, P., Brundell, J. and Johansson, G., Electroanalysis 11, 156 (1999)Google Scholar
[6] Choi, Y.-K., King, T.-J., and Hu, C., IEEE Trans. Electron Devices 49, 436 (2002)Google Scholar
[7] Hu, J., Wang, M., Weier, H., Frantz, P., Kolbe, W., Ogletree, D. and Salmeron, M., Langmuir 12, 1697 (1996)Google Scholar
[8] Sun, X., He, P., Liu, S., Ye, J. and Fang, Y., Talanta 47, 487 (1998)Google Scholar
[9] Rastogi, V.K., Singh, Chattar, Jain, Vaibhav and Palafox, M. Alcolea, J. Raman Spectrosc. 31 1005 (2000)Google Scholar
[10] Zhang, Shuliang L., Michaelian, Kirk H., and Loppnow, Glen R., J. Phys. Chem. A 102, 461 (1998)Google Scholar