Department of Chemistry, Faculty of Science, Kafrelsheikh University, Kafr El-Sheikh 33516, Egypt.
Department of Chemistry, Faculty of Science, Kafrelsheikh University, Kafr El-Sheikh 33516, Egypt; Institute of Basic and Applied Sciences, Egypt-Japan University of Science and Technology, New Borg El-Arab, Alexandria, Egypt.
Spectrochim Acta A Mol Biomol Spectrosc. 2020 Nov 5;241:118609. doi: 10.1016/j.saa.2020.118609. Epub 2020 Jun 19.
Here we report the photophysical and sensing properties of the aqueous solution of meso-tetra(N-methyl-4-pyridyl)porphyrin toluene sulfonate (TMPP) for simultaneous detection of toxic metal ions in an aqueous medium by using different physiochemical methods such as UV-vis absorption, steady state and time resolved fluorescence, stopped flow, and cyclic voltammetry. The steady-state absorption and fluorescence spectra in organic solvents (EtOH, DMSO, DMF, MeOH and ACN) showed the formation of monomer form (λ = 426 nm and λ = 654 and 715 nm). In THF and water, different spectral features were recorded suggested the formation of aggregated forms in both solvents. The formation of aggregated form in water was confirmed by recording the remarkable fluorescence quenching of the singlet excited TMPP with increasing the concentrations of TMPP. In cationic micelles (CTAB), both the absorption and fluorescence spectra were significantly decreased with increasing the concentrations of CTAB with a break at CMC value at 6.0 × 10 M. In an anionic micelle (SDS), the CMC value was found to be 1.0 × 10 M. Upon interacting with different metal ions, the absorption and fluorescence spectra of TMPP showed different features depending on the metal ions. While the optical studies of TMPP showed no significant interaction in the presence of Mn, Co, Ba, and Ni, TMPP showed that it can function as a single optical chemical sensor for the toxic metal ions in water, particularly Hg, Pb, Cu, and Cd ions.
在这里，我们报告了meso-四（N-甲基-4-吡啶基）卟啉甲苯磺酸盐（TMPP）在水溶液中的光物理和传感性质，通过使用不同的物理化学方法，如紫外可见吸收、稳态和时间分辨荧光、停流和循环伏安法，同时检测水介质中的有毒金属离子。在有机溶剂（EtOH、DMSO、DMF、MeOH 和 ACN）中的稳态吸收和荧光光谱显示形成单体形式（λ=426nm 和 λ=654nm 和 715nm）。在 THF 和水中，记录到不同的光谱特征表明在这两种溶剂中都形成了聚集态。通过记录随着 TMPP 浓度的增加，单重态激发的 TMPP 的荧光猝灭显著，证实了在水中形成了聚集态。在阳离子胶束（CTAB）中，随着 CTAB 浓度的增加，吸收和荧光光谱都显著降低，在 CMC 值 6.0×10 -5 M 处有一个转折点。在阴离子胶束（SDS）中，发现 CMC 值为 1.0×10 -4 M。与不同的金属离子相互作用时，TMPP 的吸收和荧光光谱表现出不同的特征，这取决于金属离子。虽然 TMPP 的光学研究表明在存在 Mn、Co、Ba 和 Ni 时没有明显的相互作用，但 TMPP 表明它可以作为水中有毒金属离子的单一光学化学传感器，特别是 Hg、Pb、Cu 和 Cd 离子。
