Interaction of Graphene Quantum Dots with 4-Acetamido-2,2,6,6-Tetramethylpiperidine-Oxyl Free Radicals: A Spectroscopic and Fluorimetric Study
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We report on the interaction of graphene quantum dots (GQDs) with 4-acetamido-2,2,6,6-tetramethylpiperidine-oxyl (4-acetamido-TEMPO) free radicals. The GQDs were N and S, N doped. The fluorescence quantum yields were higher for the doped GQDs compared to the undoped. The interaction is assessed by spectrofluorimetric, steady state/time resolved fluorescence and electron paramagnetic resonance (EPR) techniques. Fluorescence quenching was observed upon the addition of 4-acetamido-TEMPO to the GQDs. Photo-induced electron transfer (PET) mechanism was suggested as the plausible mechanism involved in the fluorescence quenching in which 4-acetamido-TEMPO acted as the electron acceptor.
KeywordsGraphene quantum dots Free radicals Fluorescence quenching Stern-volmer quenching constant
This work was supported by the Department of Science and Technology (DST) and National Research Foundation (NRF), South Africa, through DST/NRF South African Research Chairs Initiative for Professor of Medicinal Chemistry and Nanotechnology (UID 62620) as well as Rhodes University/DST Centre for Nanotechnology Innovation, Rhodes University, South Africa.
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There are no potential conflicts of interest with regard to this manuscript.
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Human and Animal Studies
The research does not involve human participants and/or Animals.
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