Covalent Linkages of Molecules and Proteins to Si-H Surfaces Formed by Disulfide Reduction
Thiols and disulfide contacts have been, for decades, key for connecting organic molecules to surfaces and nanoclusters as they form self-assembled monolayers (SAMs) on metals such as gold (Au) under mild conditions. In contrast, they have not been similarly deployed on Si owing to the harsh conditi...
| Main Authors: | , , , , , , , |
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| Format: | Journal Article |
| Language: | English |
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AMER CHEMICAL SOC
2020
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| Subjects: | |
| Online Access: | https://opus.lib.uts.edu.au/handle/10453/144731 http://hdl.handle.net/20.500.11937/90485 |
| _version_ | 1848765387056873472 |
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| author | Dief, Essam Vogel, Yan Peiris, Chandramalika Le Brun, A.P. Gonçales, V.R. Ciampi, Simone Reimers, J.R. Darwish, Nadim |
| author_facet | Dief, Essam Vogel, Yan Peiris, Chandramalika Le Brun, A.P. Gonçales, V.R. Ciampi, Simone Reimers, J.R. Darwish, Nadim |
| author_sort | Dief, Essam |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Thiols and disulfide contacts have been, for decades, key for connecting organic molecules to surfaces and nanoclusters as they form self-assembled monolayers (SAMs) on metals such as gold (Au) under mild conditions. In contrast, they have not been similarly deployed on Si owing to the harsh conditions required for monolayer formation. Here, we show that SAMs can be simply formed by dipping Si-H surfaces into dilute solutions of organic molecules or proteins comprising disulfide bonds. We demonstrate that S-S bonds can be spontaneously reduced on Si-H, forming covalent Si-S bonds in the presence of traces of water, and that this grafting can be catalyzed by electrochemical potential. Cyclic disulfide can be spontaneously reduced to form complete monolayers in 1 h, and the reduction can be catalyzed electrochemically to form full surface coverages within 15 min. In contrast, the kinetics of SAM formation of the cyclic disulfide molecule on Au was found to be three-fold slower than that on Si. It is also demonstrated that dilute thiol solutions can form monolayers on Si-H following oxidation to disulfides under ambient conditions; the supply of too much oxygen, however, inhibits SAM formation. The electron transfer kinetics of the Si-S-enabled SAMs on Si-H is comparable to that on Au, suggesting that Si-S contacts are electrically transmissive. We further demonstrate the prospect of this spontaneous disulfide reduction by forming a monolayer of protein azurin on a Si-H surface within 1 h. The direct reduction of disulfides on Si electrodes presents new capabilities for a range of fields, including molecular electronics, for which highly conducting SAM-electrode contacts are necessary and for emerging fields such as biomolecular electronics as disulfide linkages could be exploited to wire proteins between Si electrodes, within the context of the current Si-based technologies. |
| first_indexed | 2025-11-14T11:34:26Z |
| format | Journal Article |
| id | curtin-20.500.11937-90485 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T11:34:26Z |
| publishDate | 2020 |
| publisher | AMER CHEMICAL SOC |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-904852023-03-20T07:13:23Z Covalent Linkages of Molecules and Proteins to Si-H Surfaces Formed by Disulfide Reduction Dief, Essam Vogel, Yan Peiris, Chandramalika Le Brun, A.P. Gonçales, V.R. Ciampi, Simone Reimers, J.R. Darwish, Nadim Science & Technology Physical Sciences Technology Chemistry, Multidisciplinary Chemistry, Physical Materials Science, Multidisciplinary Chemistry Materials Science SELF-ASSEMBLED MONOLAYERS HYDROGEN-TERMINATED SILICON ALPHA-LIPOIC ACID ALKYL MONOLAYERS BOND FORMATION FUNCTIONALIZATION GOLD OXIDATION SI(100) THIOLS Thiols and disulfide contacts have been, for decades, key for connecting organic molecules to surfaces and nanoclusters as they form self-assembled monolayers (SAMs) on metals such as gold (Au) under mild conditions. In contrast, they have not been similarly deployed on Si owing to the harsh conditions required for monolayer formation. Here, we show that SAMs can be simply formed by dipping Si-H surfaces into dilute solutions of organic molecules or proteins comprising disulfide bonds. We demonstrate that S-S bonds can be spontaneously reduced on Si-H, forming covalent Si-S bonds in the presence of traces of water, and that this grafting can be catalyzed by electrochemical potential. Cyclic disulfide can be spontaneously reduced to form complete monolayers in 1 h, and the reduction can be catalyzed electrochemically to form full surface coverages within 15 min. In contrast, the kinetics of SAM formation of the cyclic disulfide molecule on Au was found to be three-fold slower than that on Si. It is also demonstrated that dilute thiol solutions can form monolayers on Si-H following oxidation to disulfides under ambient conditions; the supply of too much oxygen, however, inhibits SAM formation. The electron transfer kinetics of the Si-S-enabled SAMs on Si-H is comparable to that on Au, suggesting that Si-S contacts are electrically transmissive. We further demonstrate the prospect of this spontaneous disulfide reduction by forming a monolayer of protein azurin on a Si-H surface within 1 h. The direct reduction of disulfides on Si electrodes presents new capabilities for a range of fields, including molecular electronics, for which highly conducting SAM-electrode contacts are necessary and for emerging fields such as biomolecular electronics as disulfide linkages could be exploited to wire proteins between Si electrodes, within the context of the current Si-based technologies. 2020 Journal Article http://hdl.handle.net/20.500.11937/90485 10.1021/acs.langmuir.0c02391 English https://opus.lib.uts.edu.au/handle/10453/144731 http://purl.org/au-research/grants/arc/DP190100735 AMER CHEMICAL SOC fulltext |
| spellingShingle | Science & Technology Physical Sciences Technology Chemistry, Multidisciplinary Chemistry, Physical Materials Science, Multidisciplinary Chemistry Materials Science SELF-ASSEMBLED MONOLAYERS HYDROGEN-TERMINATED SILICON ALPHA-LIPOIC ACID ALKYL MONOLAYERS BOND FORMATION FUNCTIONALIZATION GOLD OXIDATION SI(100) THIOLS Dief, Essam Vogel, Yan Peiris, Chandramalika Le Brun, A.P. Gonçales, V.R. Ciampi, Simone Reimers, J.R. Darwish, Nadim Covalent Linkages of Molecules and Proteins to Si-H Surfaces Formed by Disulfide Reduction |
| title | Covalent Linkages of Molecules and Proteins to Si-H Surfaces Formed by Disulfide Reduction |
| title_full | Covalent Linkages of Molecules and Proteins to Si-H Surfaces Formed by Disulfide Reduction |
| title_fullStr | Covalent Linkages of Molecules and Proteins to Si-H Surfaces Formed by Disulfide Reduction |
| title_full_unstemmed | Covalent Linkages of Molecules and Proteins to Si-H Surfaces Formed by Disulfide Reduction |
| title_short | Covalent Linkages of Molecules and Proteins to Si-H Surfaces Formed by Disulfide Reduction |
| title_sort | covalent linkages of molecules and proteins to si-h surfaces formed by disulfide reduction |
| topic | Science & Technology Physical Sciences Technology Chemistry, Multidisciplinary Chemistry, Physical Materials Science, Multidisciplinary Chemistry Materials Science SELF-ASSEMBLED MONOLAYERS HYDROGEN-TERMINATED SILICON ALPHA-LIPOIC ACID ALKYL MONOLAYERS BOND FORMATION FUNCTIONALIZATION GOLD OXIDATION SI(100) THIOLS |
| url | https://opus.lib.uts.edu.au/handle/10453/144731 https://opus.lib.uts.edu.au/handle/10453/144731 http://hdl.handle.net/20.500.11937/90485 |