Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10429560 | Biosensors and Bioelectronics | 2011 | 5 Pages |
Abstract
We developed a label-free impedance biosensor based on an innovative conductive linker for detecting antibody-antigen interactions. As the often used conventional long chain thiol is a poor conductor, it is not a suitable material for use in a faradaic biosensor. In this study, we adopted a thiophene-based conductive bio-linker to form a self-assembled monolayer and to immobilize the bio-molecules. We used cyclic voltammetry and impedance spectroscopy to verify the enhanced conductivity properties. Results showed that the electron transfer resistance of this new conductive linker was 3 orders of a magnitude lower than for a case using a conventional long chain thiol linker. With the decreased impedance (i.e. increased faradaic current), we can obtain a higher signal/noise ratio such that the detection limit is improved. Using fluorescence microscopy, we verified that our new conductive linker has a protein immobilization capability similar to a conventional long chain thiol linker. Also, using S100 proteins, we verified the protein interaction detection capability of our system. Our obtained results showed a linear dynamic range from 10 ng/ml to 10 μg/ml and a detection limit of 10 ng/ml. With our new conductive linker, an electrochemical impedance biosensor shows great potential to be used for point-of-care applications.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Ching-Sung Chen, Ku-Ning Chang, Ying-Hua Chen, Chih-Kung Lee, Bryan Yong-Jay Lee, Adam Shih-Yuan Lee,