Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, WB, India.
J Phys Chem B. 2013 Aug 15;117(32):9508-17. doi: 10.1021/jp405919y. Epub 2013 Aug 7.
In this article we have reported the fluorescence resonance energy transfer (FRET) study in our earlier characterized surface active ionic liquids (SAILs)-containing microemulsion, i.e., N-methyl-N-propylpyrrolidinium bis(trifluoromethanesulfonyl)imide ([P13][Tf2N])/[CTA][AOT]/isopropyl myristate ([IPM]) and N,N,N-trimethyl-N-propylammonium bis(trifluoromethanesulfonyl)imide ([N3111][Tf2N])/[CTA][AOT]/[IPM] microemulsions (Banerjee, C.; Mandal, S.; Ghosh, S.; Kuchlyan, J.; Kundu, N.; Sarkar, N. J. Phys. Chem. B 2013, 117, 3927-3934). The occurrence of effective FRET from the donor, coumarin-153 (C-153) to the acceptor rhodamine 6G (R6G) is evident from the decrease in the steady state fluorescence intensity of the donor with addition of acceptor and subsequent increase in the fluorescence intensity of the acceptor in the presence of donor. The excitation wavelength dependent FRET from C-153 to R6G has also been performed to assess the dynamic heterogeneity of these confined systems. In time-resolved experiments, the significant rise time of the acceptor in the presence of the donor further confirms the occurrence of FRET. The multiple donor-acceptor (D-A) distances, for various microemulsions, obtained from the rise times of the acceptor emission in the presence of a donor can be rationalized from the varying distribution of the donor, C-153, in the different regions of the microemulsion. Time-resolved measurement reveals that with increasing excitation wavelength from 408 to 440 nm, the contribution of the faster rise component of FRET increases significantly due to the close proximity of the C-153 and R6G in the polar region of the microemulsion where occurrence of FRET is very high. Moreover, we have also studied the FRET with variation of R (R = [room temperature ionic liquids (RTILs)]/[surfactant]) and shown that the effect of excitation wavelength on FRET is similar irrespective of R values.
在本文中，我们报道了在我们之前表征的含有表面活性离子液体 (SAIL) 的微乳液中的荧光共振能量转移 (FRET) 研究，即 N-甲基-N-丙基吡咯烷鎓双(三氟甲烷磺酰基)亚胺 ([P13][Tf2N])/[CTA][AOT]/肉豆蔻酸异丙酯 ([IPM]) 和 N,N,N-三甲基-N-丙基铵双(三氟甲烷磺酰基)亚胺 ([N3111][Tf2N])/[CTA][AOT]/[IPM] 微乳液（Banerjee，C.；Mandal，S.；Ghosh，S.；Kuchlyan，J.；Kundu，N.；Sarkar，N. J. Phys. Chem. B 2013, 117, 3927-3934）。从供体香豆素 153 (C-153) 到受体罗丹明 6G (R6G) 的有效 FRET 的发生，从加入受体时供体的稳态荧光强度的降低以及在供体存在时受体的荧光强度的增加可以明显看出。还进行了依赖于激发波长的 C-153 到 R6G 的 FRET，以评估这些受限系统的动态异质性。在时间分辨实验中，在供体存在下，受体的显著上升时间进一步证实了 FRET 的发生。从微乳液中不同区域供体（C-153）的分布变化，可以从存在供体时受体发射的上升时间得出各种微乳液的多个供体-受体（D-A）距离。时间分辨测量表明，随着激发波长从 408 到 440nm 的增加，由于 FRET 发生的极性区域中 C-153 和 R6G 的接近，FRET 的较快上升分量的贡献显著增加。此外，我们还研究了随着 R（R = [室温离子液体 (RTILs)]/[表面活性剂]）的变化的 FRET，结果表明，激发波长对 FRET 的影响与 R 值无关。
