Department of Chemistry, University of Malakand, Khyber Pakhtunkhwa, Pakistan.
Department of Chemistry, College of Science and Arts, Najran University, P.O. Box, 1988, Najran, 11001, Saudi Arabia.
J Fluoresc. 2022 Sep;32(5):1889-1898. doi: 10.1007/s10895-022-02990-7. Epub 2022 Jun 24.
The development of a highly sensitive, selective, and efficient sensor for the determination and detection of Cr(III) ions remains a great challenge. Recently, some fluorescent chemosensors have been developed for the recognition of Cr(III) ions. But, the main drawbacks of the reported fluorescent chemosensors are the lack of selectivity and interference of anions and other trivalent cations. Herein, we designed and synthesized a novel thiazole-based fluorescent and colorimetric Schiff base chemosensor SB2 for the detection of Cr(III) ion by chemodosimetric approach. Using different analytical techniques including UV-vis, C-NMR, H-NMR, and FT-IR analysis the chemosensor SB2 was structurally characterized. The fully characterized chemosensor SB2 was used for the spectrofluorimetric and colorimetric detection of Cr(III) ions. Interestingly, chemosensor SB2 upon interaction with various metal cations including Ni, Na, Cd, Ag, Mn, K, Zn, Cu, Hg, Co, Pb, Mg, Sn, Al and Cr displays highly selective and sensitive fluorescent (turn-on) and colorimetric (yellow to colorless) response toward Cr(III) ions. The fluorescence and UV-vis techniques confirmed the selective hydrolysis of azomethine group (-C = N-) of Schiff base chemosensor SB2 by Cr(III) ions. As a result, the fluorescence enhancement was observed that is corresponding to 2-hydroxy-1-nepthaldehyde (fluorophore). The chemosensor SB2 exhibits high interference performance towards Cr(III) ions over other metal cations in a wide pH range. Mover, the quite low detection limit was calculated to be 0.027 µg ml-1 (0.5 µM) (3σ/slop), lower than the maximum tolerable limits of Cr(III ions (10 µM) in drinking water permitted by the United States Environmental Protection Agency (EPA). These results show that chemosensor SB2 has great potential to detect selectively Cr(III) ions in the agricultural, environmental and biological analysis system.
用于测定和检测 Cr(III)离子的高灵敏度、选择性和高效传感器的开发仍然是一个巨大的挑战。最近，已经开发出一些荧光化学传感器用于识别 Cr(III)离子。但是，所报道的荧光化学传感器的主要缺点是缺乏选择性和阴离子以及其他三价阳离子的干扰。在此，我们设计并合成了一种新型噻唑基荧光和比色希夫碱化学传感器 SB2，通过化学计量法用于检测 Cr(III)离子。使用包括 UV-vis、C-NMR、H-NMR 和 FT-IR 分析在内的不同分析技术对化学传感器 SB2 进行了结构表征。对完全表征的化学传感器 SB2 进行了用于检测 Cr(III)离子的光谱荧光和比色检测。有趣的是，化学传感器 SB2 与包括 Ni、Na、Cd、Ag、Mn、K、Zn、Cu、Hg、Co、Pb、Mg、Sn、Al 和 Cr 在内的各种金属阳离子相互作用时，对 Cr(III)离子表现出高度选择性和灵敏的荧光（开启）和比色（黄色变为无色）响应。荧光和 UV-vis 技术证实了 Cr(III)离子对希夫碱化学传感器 SB2 的亚胺基团（-C= N-）的选择性水解。结果，观察到荧光增强，这对应于 2-羟基-1-萘醛（荧光团）。化学传感器 SB2 在宽 pH 范围内对 Cr(III)离子具有很高的抗干扰性能，优于其他金属阳离子。此外，检测限计算为 0.027μg ml-1（0.5μM）（3σ/slop），低于美国环境保护署（EPA）允许的饮用水中 Cr(III)离子（10μM）的最大耐受限度。这些结果表明，化学传感器 SB2 具有在农业、环境和生物分析系统中选择性检测 Cr(III)离子的巨大潜力。
