Kamel Ghada M, El-Nahass Marwa N, El-Khouly Mohamed E, Fayed Tarek A, El-Kemary Maged
Department of Chemistry, Faculty of Science, Tanta University Tanta 31527 Egypt.
Department of Chemistry, Faculty of Science, Kafrelsheikh University Kafr El-Sheikh 33516 Egypt.
RSC Adv. 2019 Mar 13;9(15):8355-8363. doi: 10.1039/c9ra00464e. eCollection 2019 Mar 12.
Toward the goal of detecting toxic elements and removing them from drinking water, we report herein the utilization of Acid Red 94 (AR94) in sensing the hazardous metal ions in water. Among the various examined metal ions (Ag, Pb, K, Mn, Zn, La, Hg, Ca, Cd, Co, and Ni), the UV-visible absorption spectra showed high selectivity and sensitivity for toxic silver and lead metal ions in an aqueous solution. The observed absorption spectral changes and the rapid color changes confirm complex formation between AR94 and both Ag and Pb metal ions. The emission measurements showed the significant fluorescence quenching of the singlet excited state of AR94 in the presence of Ag and Pb metal ions suggesting the formation of an irradiative dye-metal complex under the prevailing experimental conditions. In order to remove the accumulated complexes of AR94 with silver metal ions, safe and harmless mesoporous titanium dioxide was utilized efficiently in removing the complexes with adsorption capacities of 91% at 30 minutes. These findings suggest a simple, fast and efficient method for both detecting silver in water, and removing the formed AR94-metal complexes in water. In addition, AR94 is shown to be a good sensor for the presence of Ag and Pb nanoparticles, NPs, in aqueous solution. The absorption and emission spectra of AR94 showed significant changes that may be rationalized by the strong electromagnetic coupling induced by NPs plasmonic effects. These findings render AR94 a sensitive and selective sensor and a visual indicator for the qualitative and quantitative detection of silver ions, lead ions and their nanoparticles.
为了实现检测有毒元素并将其从饮用水中去除的目标，我们在此报告利用酸性红94（AR94）来传感水中的有害金属离子。在各种被检测的金属离子（银、铅、钾、锰、锌、镧、汞、钙、镉、钴和镍）中，紫外可见吸收光谱显示出对水溶液中有毒的银和铅金属离子具有高选择性和灵敏度。观察到的吸收光谱变化和快速的颜色变化证实了AR94与银和铅金属离子之间形成了络合物。发射测量表明，在银和铅金属离子存在的情况下，AR94单重激发态的荧光显著猝灭，这表明在当前实验条件下形成了辐射性的染料-金属络合物。为了去除AR94与银金属离子积累形成的络合物，安全无害的介孔二氧化钛被有效地用于去除络合物，在30分钟时吸附容量达到91%。这些发现表明了一种简单、快速且高效的方法，既能检测水中的银，又能去除水中形成的AR94-金属络合物。此外，AR94被证明是水溶液中银和铅纳米颗粒（NPs）存在的良好传感器。AR94的吸收和发射光谱显示出显著变化，这可以通过纳米颗粒等离子体效应引起的强电磁耦合来解释。这些发现使AR94成为一种灵敏且选择性的传感器，以及用于银离子、铅离子及其纳米颗粒定性和定量检测的视觉指示剂。
