Banerjee R, Sinha R, Purkayastha P. β-Cyclodextrin Encapsulated Coumarin 6 on Graphene Oxide Nanosheets: Impact on Ground-State Electron Transfer and Excited-State Energy Transfer.
ACS OMEGA 2019;
4:16153-16158. [PMID:
31592159 PMCID:
PMC6777122 DOI:
10.1021/acsomega.9b02335]
[Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 09/06/2019] [Indexed: 06/10/2023]
Abstract
We report a unique phenomenon of physical adsorption of coumarin 6-β-cyclodextrin (C6-β-CD) inclusion nanostructures on graphene oxide (GO) nanosheets, thus inducing ground-state electron transfer from the C6-β-CD composite to GO. On excitation, the C6-β-CD composite initially transfers energy to the attached GO surface and subsequently collides with similar C6-β-CD@GO adducts leading to dynamic quenching of energy. The ground-state two-electron transfer process has been confirmed by cyclic voltammetry in aqueous medium, whereas the excited-state processes were inferred from steady-state and time-resolved fluorescence spectroscopy. The concept is developed toward conceiving control over the ground-state electron transfer and excited state energy transfer from the C6-β-CD composite by the adsorbed electron accepting medium (GO in this case). The C6-β-CD composite has been prepared to isolate single C6 molecules that readily undergo microcrystal formation in aqueous medium. The results show its potential toward fabrication of energy-harvesting antenna for further applications.
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