▎ 摘　　要

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 (lambda(ex): 328 nm). UV?visible and fluorescence spectroscopy findings on the interaction of GNB with Ce3+ confirm the binding stoichiometry as 1:1 (K-a = 4.85 x 10(-3) and 2.22 x 10(-2) M, respectively) with a LoD ca. 35.0 mu M (S/N = 3). The fluorescence decay profile experiment reveals the formation of a ground-state complex, GNB-Ce3+, with an increase in lifetime (tau 7.02 -> 27.01 ns), and fluorescence quantum yield (Phi(F) 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 (TDDFT) 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.