Department of Chemical Engineering, Thapar Institute of Engineering and Technology, Patiala, India.
Analyst. 2020 Sep 28;145(19):6378-6387. doi: 10.1039/d0an00717j.
The development of a sensitive α-NaYF4:Yb3+,Er3+ solid-phase upconverting platform (UCP) was realized using Moringa oleifera leaf extract for selective detection of the trivalent arsenic ion [As(iii)] contamination in drinking water. The presence of polyphenols in the leaf extract were shown to induce luminescence resonance transfer (LRET), thereby diminishing the Er3+ emission (red and green band) when activated by 980 nm excitation. However, the addition of As(iii) species interrupted the LRET process and restored the emissions proportionately. This feature allowed the platform to selectively detect arsenic pollution in water below the safe limit of 10 ppt. The uniqueness of UCP lies in monitoring the As(iii) contamination in samples containing heavy ions (Cd2+ and Hg2+) also, without an apparent effect on the signal reproducibility. The UCP was also found to be insensitive to other interfering ions including Pb2+, H2PO4-, F-, Cl-, Ca2+, Mg2+, Sn2+, Cr6+, Fe2+ and Co2+, if present.
利用辣木叶提取物开发了一种灵敏的α-NaYF4:Yb3+,Er3+ 固相聚光上转换平台 (UCP)，用于选择性检测饮用水中三价砷离子 [As(iii)] 的污染。叶提取物中存在的多酚被证明会诱导发光共振转移 (LRET)，从而在 980nm 激发下减少 Er3+ 的发射（红色和绿色波段）。然而，添加 As(iii) 物种会中断 LRET 过程，并按比例恢复发射。该特性使该平台能够选择性地检测水中低于 10ppt 的安全限量的砷污染。UCP 的独特之处在于能够监测含有重金属离子（Cd2+和 Hg2+）的样品中的 As(iii) 污染，而对信号重现性没有明显影响。研究还发现，UCP 对其他干扰离子（包括 Pb2+、H2PO4-、F-、Cl-、Ca2+、Mg2+、Sn2+、Cr6+、Fe2+和 Co2+）的存在不敏感。
