Abstract:

Highly sensitive and selective detection of Hg²⁺ in water is of great significance for human health and eco-environmental sustainability. In this work, based on microstructure adjustment and signal conversion via selective and strong chelation between thiourea groups and Hg²⁺, a Hg²⁺-responsive smart hydrogel grating was created for ultrasensitive, highly-selective and facile detection of trace Hg²⁺ in water. In the crosslinked polymeric networks of the hydrogel grating, the thiourea groups can selectively chelate with Hg²⁺ to induce the height change of the hydrogel grating, thus realizing the signal conversion from concentration change of Hg²⁺ to intensity change of diffracted light. By integrating the hydrogel grating into an optical detection system to conveniently detect the intensity changes of diffracted light, ultrasensitive and highly-selective detection of Hg²⁺ with concentration as low as 10^-9 mol/L in water can be achieved. This work provided a new strategy for development of convenient and sensitive detection technique for trace Hg²⁺ in water.

Key words: smart hydrogel, grating, mercury (Ⅱ) ion, chelation

摘要：

高灵敏度、高选择性检测水中Hg²⁺对于人类健康和环境生态可持续发展具有重要意义。本文基于硫脲基团与Hg²⁺的选择性强螯合作用来调控光栅微结构和实现信号转化，构建了用于高灵敏、高选择性便捷检测水中痕量Hg²⁺的智能凝胶光栅。该凝胶光栅的交联高分子网络结构中具有硫脲基团，可高选择性地与Hg²⁺进行强螯合，从而诱导光栅起伏高度发生变化，实现由水中Hg²⁺浓度到衍射光强度的信号变化。通过利用该智能凝胶光栅构建光学检测系统来便捷检测衍射光强度变化，可高灵敏、高选择性地检测水中浓度低至10^-9mol/L的Hg²⁺。相关工作为面向水中痕量Hg²⁺的便捷灵敏检测技术的开发提供了新途径。

关键词: 智能凝胶, 光栅, 汞离子, 螯合作用