BROWSE
Detail
Journal Article
Sublithographic Vertical Gold Nanogap for Label-free Electrical Detection of Protein-ligand Binding
- Authors
- Dong-Yoon Jang, Young-Pil Kim, Hak-Sung Kim, Sang-Hee Ko Park, Sung-Yool Choi, Yang-Kyu Choi
- Issue Date
- 2007-03
- Citation
- Journal of Vacuum Science and Technology B, v.25, no.2, pp.443-447
- ISSN
- 1071-1023
- Publisher
- American Vacuum Society (AVS)
- Language
- English
- Type
- Journal Article
- Abstract
- Label-free electrical detection of protein-ligand binding using a vertical gold nanogap is presented. A sublithographic nanogap was created using a sacrificial ultrathin film deposited by atomic layer deposition (ALD) in a process similar to the formation of a cantilever in microelectromechanical system processing. Due to the atomic precision of the sacrificial Al 2O3 thickness by ALD, a 7 nm nanogap was successfully fabricated. After binding streptavidin to biotin on the gold surface, an electrical current was measured for various voltages. A dramatic current increase was observed in the case of biotin-streptavidin binding in comparison with the other two cases: a control group filled with air and a biotin-only binding group. There was a minimal current change in the cases of the biotin-PBST group, the biotin-BSA group, and the biotin-saturated streptavidin group, as compared with the biotin-streptavidin group. At a 0.1 μg/ml concentration of streptavidin (1.5 nM), the current difference before and after the protein binding was amplified by approximately 3000-fold with 17 nm nanogap. Also, the detection sensitivity of the vertical nanogap as the gap size varied was investigated. As the size of biotin-streptavidin binding is the most comparable to 12 nm nanogap, the highest sensitivity was shown in the 12 nm gap device. 7 nm nanogap can be used to detect smaller size of biomolecule than that of biotin streptavidin. This arrayable, two-terminal microdevice could be tested for use on a wide range of other biomolecules. © 2007 American Vacuum Society.
- KSP Keywords
- 5 nm, Atomic Layer Deposition, Biotin-streptavidin binding, Current difference, Detection sensitivity, Gold surface, Label-free electrical detection, Micro-electro-mechanical system(MEMS), Ultrathin film, Wide range, atomic precision
This work is distributed under the term of Creative Commons License (CCL)
(CC BY)
(CC BY)
