Atomic force microscopy evidence of citrate displacement by 4-mercaptopyridine on gold in aqueous solution
The displacement adsorption process of 4-mercaptopyridine (4-MP) on trisodium citrate preadsorbed gold surface in aqueous solution was studied using atomic force microscopy (AFM). The measurement was done by monitoring the interaction force between a gold-coated AFM tip and a gold substrate, both pr...
| Main Authors: | , , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2012
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| Online Access: | https://hdl.handle.net/10356/95278 http://hdl.handle.net/10220/8627 |
| _version_ | 1826112503370743808 |
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| author | Zhang, Hua He, Hui-Xin Wang, Jian Liu, Zhong-Fan |
| author2 | School of Materials Science & Engineering |
| author_facet | School of Materials Science & Engineering Zhang, Hua He, Hui-Xin Wang, Jian Liu, Zhong-Fan |
| author_sort | Zhang, Hua |
| collection | NTU |
| description | The displacement adsorption process of 4-mercaptopyridine (4-MP) on trisodium citrate preadsorbed gold surface in aqueous solution was studied using atomic force microscopy (AFM). The measurement was done by monitoring the interaction force between a gold-coated AFM tip and a gold substrate, both presaturated by trisodium citrate. The addition of 4-MP was found to result in a remarkable change of tip−substrate adhesion force, which showed a gradual increase and finally reached a maximum. Using the chemical force titration technique, we estimated the surface pK1/2 of thus-formed 4-MP displacement film and compared with pure 4-MP self-assembled monolayer (SAM) formed on gold in ethanol solution. Our results indicate that the 4-MP molecules are more strongly adsorbed on gold than citrate anions, mostly via Au−S bonding, forming a less dense and mixed displacement film. The displacement adsorption kinetics seems very fast and it takes only ca. 2 min to establish more than 50% surface coverage of 4-MP molecules. |
| first_indexed | 2024-10-01T03:08:06Z |
| format | Journal Article |
| id | ntu-10356/95278 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T03:08:06Z |
| publishDate | 2012 |
| record_format | dspace |
| spelling | ntu-10356/952782020-06-01T10:01:34Z Atomic force microscopy evidence of citrate displacement by 4-mercaptopyridine on gold in aqueous solution Zhang, Hua He, Hui-Xin Wang, Jian Liu, Zhong-Fan School of Materials Science & Engineering DRNTU::Engineering::Materials The displacement adsorption process of 4-mercaptopyridine (4-MP) on trisodium citrate preadsorbed gold surface in aqueous solution was studied using atomic force microscopy (AFM). The measurement was done by monitoring the interaction force between a gold-coated AFM tip and a gold substrate, both presaturated by trisodium citrate. The addition of 4-MP was found to result in a remarkable change of tip−substrate adhesion force, which showed a gradual increase and finally reached a maximum. Using the chemical force titration technique, we estimated the surface pK1/2 of thus-formed 4-MP displacement film and compared with pure 4-MP self-assembled monolayer (SAM) formed on gold in ethanol solution. Our results indicate that the 4-MP molecules are more strongly adsorbed on gold than citrate anions, mostly via Au−S bonding, forming a less dense and mixed displacement film. The displacement adsorption kinetics seems very fast and it takes only ca. 2 min to establish more than 50% surface coverage of 4-MP molecules. 2012-09-24T07:41:00Z 2019-12-06T19:11:44Z 2012-09-24T07:41:00Z 2019-12-06T19:11:44Z 2000 2000 Journal Article Zhang, H., He, H. X., Wang, J., & Liu, Z. F. (2000). Atomic force microscopy evidence of citrate displacement by 4-mercaptopyridine on gold in aqueous solution. Langmuir, 16(10), 4554-4557. 0743-7463 https://hdl.handle.net/10356/95278 http://hdl.handle.net/10220/8627 10.1021/la9904657 en Langmuir © 2000 American Chemical Society. |
| spellingShingle | DRNTU::Engineering::Materials Zhang, Hua He, Hui-Xin Wang, Jian Liu, Zhong-Fan Atomic force microscopy evidence of citrate displacement by 4-mercaptopyridine on gold in aqueous solution |
| title | Atomic force microscopy evidence of citrate displacement by 4-mercaptopyridine on gold in aqueous solution |
| title_full | Atomic force microscopy evidence of citrate displacement by 4-mercaptopyridine on gold in aqueous solution |
| title_fullStr | Atomic force microscopy evidence of citrate displacement by 4-mercaptopyridine on gold in aqueous solution |
| title_full_unstemmed | Atomic force microscopy evidence of citrate displacement by 4-mercaptopyridine on gold in aqueous solution |
| title_short | Atomic force microscopy evidence of citrate displacement by 4-mercaptopyridine on gold in aqueous solution |
| title_sort | atomic force microscopy evidence of citrate displacement by 4 mercaptopyridine on gold in aqueous solution |
| topic | DRNTU::Engineering::Materials |
| url | https://hdl.handle.net/10356/95278 http://hdl.handle.net/10220/8627 |
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