Journal
BIOSENSORS & BIOELECTRONICS
Volume 40, Issue 1, Pages 227-232Publisher
ELSEVIER ADVANCED TECHNOLOGY
DOI: 10.1016/j.bios.2012.07.028
Keywords
Capacitive; Immunoassay; Non-labeled detection; Parylene-C; Impedance
Ask authors/readers for more resources
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. (C) 2012 Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available