l-tryptophan adsorption differentially changes the optical behaviour of pseudo-enantiomeric cysteine-functionalized quantum dots: Towards chiral fluorescent biosensors
Water-soluble chiral graphene quantum dots (GQDs) with a strong blue emission were synthesized by covalently immobilizing l-cysteine or d-cysteine onto the GQDs. Either the amine or the thiol group of cysteine was used to make the bond through amide coupling or thiol-ene click chemistry respectively...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2019-02-01
|
| Series: | Sensing and Bio-Sensing Research |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S221418041830117X |
| _version_ | 1817996473806094336 |
|---|---|
| author | Faezeh Askari Abbas Rahdar John F. Trant |
| author_facet | Faezeh Askari Abbas Rahdar John F. Trant |
| author_sort | Faezeh Askari |
| collection | DOAJ |
| description | Water-soluble chiral graphene quantum dots (GQDs) with a strong blue emission were synthesized by covalently immobilizing l-cysteine or d-cysteine onto the GQDs. Either the amine or the thiol group of cysteine was used to make the bond through amide coupling or thiol-ene click chemistry respectively. The functionalized chiral GQDs were the characterized by FT-IR and UV–vis. The enantiomeric pairs exhibit equal but opposite bands in circular dichroism spectra suggesting that there is no difference in the efficacy of conjugation. The fluorescent response of these chiral GQDs when exposed to l-tryptophan was then studied. The fluorescence of the amide-conjugated GQDs was quenched with the addition of l-Trp regardless of which enantiomer of cysteine was present on the surface. The thiol-linked d- Cys GQDs fluorescence was also quenched on exposure to l-Trp, but the fluorescence of the thiol-linked l-Cys GQDs was unaffected under the same conditions. Keywords: Graphene quantum dots, Click chemistry, Chiral sensors, Circular dichroism, Fluorescence |
| first_indexed | 2024-04-14T02:22:48Z |
| format | Article |
| id | doaj.art-1f57d17bc6c54fe9a22527238c948084 |
| institution | Directory Open Access Journal |
| issn | 2214-1804 |
| language | English |
| last_indexed | 2024-04-14T02:22:48Z |
| publishDate | 2019-02-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Sensing and Bio-Sensing Research |
| spelling | doaj.art-1f57d17bc6c54fe9a22527238c9480842022-12-22T02:17:58ZengElsevierSensing and Bio-Sensing Research2214-18042019-02-0122l-tryptophan adsorption differentially changes the optical behaviour of pseudo-enantiomeric cysteine-functionalized quantum dots: Towards chiral fluorescent biosensorsFaezeh Askari0Abbas Rahdar1John F. Trant2Department of Physics, University of Zabol, Zabol, P. O. Box. 35856-98613, Islamic Republic of IranDepartment of Physics, University of Zabol, Zabol, P. O. Box. 35856-98613, Islamic Republic of Iran; Corresponding authors.Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada; Corresponding authors.Water-soluble chiral graphene quantum dots (GQDs) with a strong blue emission were synthesized by covalently immobilizing l-cysteine or d-cysteine onto the GQDs. Either the amine or the thiol group of cysteine was used to make the bond through amide coupling or thiol-ene click chemistry respectively. The functionalized chiral GQDs were the characterized by FT-IR and UV–vis. The enantiomeric pairs exhibit equal but opposite bands in circular dichroism spectra suggesting that there is no difference in the efficacy of conjugation. The fluorescent response of these chiral GQDs when exposed to l-tryptophan was then studied. The fluorescence of the amide-conjugated GQDs was quenched with the addition of l-Trp regardless of which enantiomer of cysteine was present on the surface. The thiol-linked d- Cys GQDs fluorescence was also quenched on exposure to l-Trp, but the fluorescence of the thiol-linked l-Cys GQDs was unaffected under the same conditions. Keywords: Graphene quantum dots, Click chemistry, Chiral sensors, Circular dichroism, Fluorescencehttp://www.sciencedirect.com/science/article/pii/S221418041830117X |
| spellingShingle | Faezeh Askari Abbas Rahdar John F. Trant l-tryptophan adsorption differentially changes the optical behaviour of pseudo-enantiomeric cysteine-functionalized quantum dots: Towards chiral fluorescent biosensors Sensing and Bio-Sensing Research |
| title | l-tryptophan adsorption differentially changes the optical behaviour of pseudo-enantiomeric cysteine-functionalized quantum dots: Towards chiral fluorescent biosensors |
| title_full | l-tryptophan adsorption differentially changes the optical behaviour of pseudo-enantiomeric cysteine-functionalized quantum dots: Towards chiral fluorescent biosensors |
| title_fullStr | l-tryptophan adsorption differentially changes the optical behaviour of pseudo-enantiomeric cysteine-functionalized quantum dots: Towards chiral fluorescent biosensors |
| title_full_unstemmed | l-tryptophan adsorption differentially changes the optical behaviour of pseudo-enantiomeric cysteine-functionalized quantum dots: Towards chiral fluorescent biosensors |
| title_short | l-tryptophan adsorption differentially changes the optical behaviour of pseudo-enantiomeric cysteine-functionalized quantum dots: Towards chiral fluorescent biosensors |
| title_sort | l tryptophan adsorption differentially changes the optical behaviour of pseudo enantiomeric cysteine functionalized quantum dots towards chiral fluorescent biosensors |
| url | http://www.sciencedirect.com/science/article/pii/S221418041830117X |
| work_keys_str_mv | AT faezehaskari ltryptophanadsorptiondifferentiallychangestheopticalbehaviourofpseudoenantiomericcysteinefunctionalizedquantumdotstowardschiralfluorescentbiosensors AT abbasrahdar ltryptophanadsorptiondifferentiallychangestheopticalbehaviourofpseudoenantiomericcysteinefunctionalizedquantumdotstowardschiralfluorescentbiosensors AT johnftrant ltryptophanadsorptiondifferentiallychangestheopticalbehaviourofpseudoenantiomericcysteinefunctionalizedquantumdotstowardschiralfluorescentbiosensors |