Al-based metal-organic gels for selective fluorescence recognition of hydroxyl nitro aromatic compounds

作者：Guo, Mao Xia; Yang, Liu; Jiang, Zhong Wei; Peng, Zhe Wei; Li, Yuan Fang^*

来源：Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy , 2017, 187: 43-48.

DOI：10.1016/j.saa.2017.05.057

• Metal-organic gels
• Fluorescence
• Nitro aromatic compounds
• Stimuli-responsive

The novel class of luminescent Al3+-based metal-organic gels (Al-MOGs) have been developed by mix 4-[2,2':6',2 ''-terpyridine]-4'-ylbenzoic acid (Hcptpy) with Al3+ under mild condition. The as-prepared Al-MOGs have not only multiple stimuli-responsive properties, but selective recognition of hydroxyl nitro aromatic compounds, which can quench the fluorescence of the Al-MOGs, while other nitro aromatic analogues without hydroxyl substitutes cannot. The fluorescence of Al-MOGs at 467 nm was seriously quenched by picric acid (PA) whose lowest unoccupied molecular orbital (LUMO) energy levels are lower than those of three other hydroxyl nitro aromatic compounds including 4-nitrophenol (4-NP), 3,5-dinitrosalicylic acid (3,5-DNTSA) and 2,4-dinitrophenol (2,4-DNP). Thus, PA was chosen as a model compound under optimal conditions and the relative fluorescence intensity of Al-MOGs was proportional to the concentration of PA in the range of 5.0-320.0 mu M with a detection limit of 4.64 mu M. Furthermore, the fluorescence quenching mechanism has also been investigated and revealed that the quenching was attributed to inner filter effects (IFEs), as well as electron transfer (ET) between Al-MOGs and PA.

• 出版日期2017-12-5
• 单位西南大学