Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7234596 | Biosensors and Bioelectronics | 2013 | 6 Pages |
Abstract
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 50Â nm and 100Â nm, and a parylene-C film with a thickness of 550Â 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.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Ga-Yeon Lee, Yong-Hwan Choi, Ha-Wook Chung, Hyuk Ko, Sungbo Cho, Jae-Chul Pyun,