Phenanthrene-imidazole-based fluorescent sensor for selective detection of Ag+ and F− ions: real sample application and live cell imaging
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4-Methyl-2,6-bis(1H-phenanthro[9,10-d]imidazol-2-yl)phenol (probe-MPIP) conjugate has been designed as a selective fluorescent probe for silver (Ag+) ions. The probe-MPIP exhibits selectivity towards Ag+ in DMSO-H2O (1:9 v/v) in 50 mM HEPES (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid) at pH 7.4. Moreover, the detection of probe-MPIP towards Ag+ ions could be realized with a “naked eye” with a color conversion from greenish yellow to orange. The linear relationship between fluorescence intensity and Ag+ ion concentration indicates that probe-MPIP can be used for quantification of Ag+ ions. The probe-MPIP can be used in a broad range of pH from 3 to 11. The limit of detection (LOD) and association constant (Ka) of MPIP-Ag+ complex have been determined and found to be 1.8 nM and 8.24 × 105 M−1, respectively, according to fluorescence titrations. Moreover, the binding ratio of probe-MPIP and Ag+ was found to be 1:1 by Job’s method. Furthermore, MPIP-Ag+ complex subsequently acted as a secondary fluorescent turn-on probe for fluoride (F−) ion recognition among the other anions. To assess the real-world efficacy of probe-MPIP and MPIP-Ag+ complex, a real water sample of silver and fluoride ions (Ag+ and F−) was evaluated. Furthermore, probe-MPIP and MPIP-Ag+ complex have been successfully applied to cell imaging studies.
KeywordsFluorescent probe Silver and fluoride ion detection Binding constant Real sample analysis In vitro cell imaging
One of the authors (A.G.) thanks the Department of Science and Technology, Ministry of Science and Technology, Government of India, for a fellowship under the INSPIRE scheme (no. IF140098).
- 37.C.J. Chen, A.J. Zhang, J.B. Hu, Y.H. Miao, X. Liu, Tet. Lett. 435, 137 (2015)Google Scholar