Assembly Modulation of PDI Derivative as a Supramolecular Fluorescence Switching Probe for Detection of Cationic Surfactant and Metal Ions in Aqueous Media
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- 作者：Atul K. Dwivedi ; M. Pandeeswar ; T. Govindaraju
- 刊名：ACS Applied Materials & Interfaces
- 出版年：2014
- 出版时间：December 10, 2014
- 年：2014
- 卷：6
- 期：23
- 页码：21369-21379
- 全文大小：688K
- ISSN：1944-8252
文摘
We report an amphiphilic perylene diimide (1), a bimolecular analog of l-3,4-dihydroxyphenylalanine (L-DOPA), as a reversible fluorescence switching probe for the detection and sensing of cationic surfactants and Fe3+/Cu2+ in an aqueous media respectively by means of host鈥揼uest interactions driven assembly and disassembly of 1. Photophysical studies of 1, going from dimethyl sulfoxide (DMSO) (State-I) to pure aqueous medium (State-II), suggested the formation of self-assembled aggregates by displaying very weak fluorescence emission along with red shifted broad absorption bands. Interestingly, the cationic surfactant cetyltrimethylammonium bromide (CTAB) could disassemble 1 in miceller conditions by restoring bright yellow fluorescence and vibronically well-defined (Franck鈥揅ondon progressions A0鈥?/A0鈥? 鈮?1.6) absorption bands of 1 over other neutral and anionic surfactants (State-III). Owing to the metal chelating nature of L-DOPA, 1 was able to sense Fe3+ and Cu2+ among a pool of other metal ions by means of fluorescence switching off state, attributed to metal interaction driven assembly of 1 (State-IV). Such metallosupramolecular assemblies were found to reverse back to the fluorescence switching on state using a metal ion chelator, diethylenetriaminepentaacetic acid (DTPA, State-III), further signifying the role of metal ions toward assembly of 1. Formation of assembly and disassembly could be visualized by the diminished and increased yellow emission under green laser light. Further, the assembly鈥揹isassembly modulation of 1 has been extensively characterized using infrared (IR), mass spectrometry, microscopy and dynamic light scattering (DLS) techniques. Therefore, modulation of the molecular self-assembly of PDI derivative 1 in aqueous media (assembled state, State-II) by means of host鈥揼uest interactions provided by micellar structures of CTAB (disassembled state, State-III), metal ion (Fe3+ and Cu2+) interactions (assembled state, State-IV) and metal ion sequestration using DTPA (disassembled state, State-III) is viewed as a supramolecular reversible fluorescence switching off鈥搊n probe for cationic surfactant CTAB and Fe3+/Cu2+.