Investigation on surface interaction between graphene nanobuds and cerium(III) via fluorescence excimer, theoretical, real water sample, and bioimaging studies

• Published in: Materials chemistry and physics Vol. 264; p. 124453
• Main Authors: Pavithra, V.R., Daniel Thangadurai, T., Manonmani, G., Senthilkumar, K., Nataraj, D., Jiya, J., Nandakumar, K., Thomas, S.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.05.2021; Elsevier BV
• Subjects: Bioimaging; Cerium; Cerium (III); Chelation; DFT studies; Energy levels; Epithelium; Excimer; Excimers; Fluorescence; Graphene; Graphene nanobud; Medical imaging; Molecular orbitals; Stoichiometry; Toxicity testing; Water samples; Water sampling; Cerium (III); Bioimaging; DFT studies; Excimer; Graphene nanobud; Water samples
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2021.124453

Graphene nanobud (GNBs) with an average size of ca. 35–40 nm was utilized to determine the micromolar concentration of Ce3+via chelation-induced fluorescence excimer formation (CHEF) at 475 nm (λex: 328 nm). UV–visible and fluorescence spectroscopy findings on the interaction of GNB with Ce3+ confirm the binding stoichiometry as 1:1 (Ka = 4.85 × 10−3 and 2.22 × 10−2 M, respectively) with a LoD ca. 35.0 μM (S/N = 3). The fluorescence decay profile experiment reveals the formation of a ground-state complex, GNB∙Ce3+, with an increase in lifetime (τ 7.02 → 27.01 ns), and fluorescence quantum yield (ФF 53.6 → 85.0%). Interference of other metal ions (M1+/2+/3+), the effect of solvent polarity, and the effect of time on the selective determination of Ce3+, and reversibility and the stability of GNB∙Ce3+ complex were examined. Theoretical calculation (TD-DFT) on the effect of molecular orbital energy levels of GNBs upon interaction with Ce3+ was investigated. Detection of Ce3+ in relevant water samples enriches the real-world application of GNBs which brings the futuristic application to sense Ce3+ in living cell lines. To accentuate, bioimaging of Ce3+ in living human breast cancer and human epithelial cells, and cytotoxicity test was successfully demonstrated. Confocal Raman microscopy images and corresponding spectrum articulated the practicability of GNBs in biological systems. [Display omitted] •First report on surface interaction of graphene nanobuds (GNBs; size ca. 35–40 nm) with Ce3+ in H2O.•GNBs showed excellent LoD ca. 35.0 μM with “turn-on” fluorescence excimer formation.•Required only <1 min to interact with Ce3+ over other interferon M1+/2+/3+ ions.•Developed method was successfully applied to relevant real water sample analysis.•GNBs could be an alternate fluorescent dye in live HeLa and human epithelial cell bioimaging.