Capacitive immunoaffinity biosensor based on vertically paired ring-electrodes

Ga Yeon Lee, Yong Hwan Choi, Ha Wook Chung, Hyuk Ko, Sungbo Cho, Jae Chul Pyun

Research output: Contribution to journalArticlepeer-review

23 Citations (Scopus)


A capacitive biosensor was developed by using a vertically paired ring-electrode for the non-labeled immunoassay. The vertically paired ring-electrode was prepared by sequential deposition and etching processes. Two electrodes were layered on glass substrate by sputtering of gold layers with thicknesses of 50 nm and 100 nm, and a parylene-C film with a thickness of 550. nm was positioned between the electrode layers as a dielectric material by thermal deposition. The top layer was made by spin coating of SU-8. And then, the ring-electrodes were exposed at the wall of the layered structure by sequential etching processes. The fabricated electrodes were characterized by cyclic voltammetry of a well-known redox couple of 3,3',5,5'-tetramethylbenzidine. The non-labeled detection of antigen-antibody interaction was demonstrated by using anti-horseradish peroxidase (HRP) antibodies and C-reactive protein (CRP) as model analytes. When the model analytes were bound to the vertically paired ring-electrode, the impedance change was measured during the immunoassay steps, and the measured impedance was analyzed by using a model circuit of the ring-electrode, and the capacitance was estimated to be dependent on the adsorption of analytes between the ring-electrodes.

Original languageEnglish
Pages (from-to)227-232
Number of pages6
JournalBiosensors and Bioelectronics
Issue number1
Publication statusPublished - 2013 Feb 15

Bibliographical note

Funding Information:
This work was supported by DAPA and ADD . This research was also supported by the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology ( 2009-0082188 , 2009-008-1529 , 2010-0020772 and 2011-0020285 ).

All Science Journal Classification (ASJC) codes

  • Biotechnology
  • Biophysics
  • Biomedical Engineering
  • Electrochemistry


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