基于金属纳米材料气-液/固非均相反应的重金属可视化检测及其在乡村环境分析中的应用

In China, there are more serious heavy metal pollution problems in rural than in cities. The development of portable detection technologies and methods for heavy metals has important application value and social significance in promoting the green development of rural areas. Using metal nanomaterials to build heavy metal colorimetric sensors has many advantages, such as high sensitivity, good selectivity and simple instruments. When it is applied to the field environment detection, however, improving the stability and reducing the matrix interference are the problems that must be solved. This project aims to develop a new visual detection method based on gas-liquid/solid nonhomogeneous reaction via metal nanomaterials. The colorimetric response will be produced by the reaction between the metal nanomaterial and the heavy metal in its gaseous form separated from the matrix by chemical vapor. Thus, the matrix effect will be greatly reduced or eliminated and various samples including complex, colored or turbidity ones can be used in this rapid colorimetric determination. To achieve high stability and selectivity, the functionalization of different morphologies of metal nanomaterials will be accomplished through the specific interaction among the vapor species containing heavy metals, nanomaterials and ligands. This economical, simple, stable and efficient method will first be used in the field testing of environmental samples in rural areas around Chengdu city. This project will provide new research ideas and ways for the establishment of the heavy metal portable detection which is suitable for the rural environment analysis.

我国乡村存在着比城市更严重的重金属污染问题，研发重金属便携检测技术和方法在促进乡村绿色发展中具有重要的应用价值和社会意义。用金属纳米材料构建重金属的比色传感器，具有灵敏度高、选择性好、仪器简单等优点，但要应用于现场环境检测，提高稳定性和减小基体干扰是必须解决的难题之一。本项目拟发展基于金属纳米材料气-液/固非均相反应的重金属可视化检测新方法，建立新型比色检测装置；重金属通过化学蒸气发生脱离基体以气态形式与金属纳米材料产生比色响应，基体效应从而显著降低或消除，包括复杂基体、有色、浑浊的各类样品可实现快速比色测定。对不同形貌的金属纳米材料修饰功能化，利用重金属蒸气、纳米材料、配体之间的特异性作用，实现重金属的稳定、高选择性地检测，并将其先用到成都市区周边农村环境样品实地检测中。该方法将具有经济、简便、稳定、高效的特点，为建立适用于广大乡村环境分析的重金属便携检测提供新的研究思路和途径。

研发高灵敏、抗干扰、稳定高效的重金属可视化检测新技术和新方法是适应现场快速环境分析检测需求与发展的重要趋势，也是助力乡村绿色发展的有效环境检测手段。本项目将化学蒸气发生与金属纳米材料的比色测定相结合，通过气-液/固非均相反应构建了一系列新颖的可视化检测新方法和新装置。将氢化物发生与牛血清白蛋白修饰的金团簇的顶空荧光传感相结合，建立了简单的“试纸”形式的比色检测硒的新方法，并通过理论计算揭示了金团簇催化和荧光淬灭的双功能响应机制。除化学蒸气发生与金纳米材料直接反应的模式外，我们还利用氢化物的强还原性，在碘离子催化和聚合物稳定作用下，通过原位形成金纳米，建立了测定痕量砷的新方法，并研发了具有气液分离功能、易操作观察颜色变化的平台液珠式顶空比色的新装置。我们开创了顶空纳米酶放大传感新模式，将纳米酶顶空萃取与化学蒸气发生结合，通过酶促反应放大比色和荧光传感信号，实现汞的便携比色和智能手机数字检测。这些非均相反应方法能高效地避免基质干扰，灵敏度高，选择性好，已成功应用于各类环境和生物样品中痕量砷、汞、硒的检测。研究结果提高了重金属检测的分析性能并拓展了现场分析的应用范围，同时也为发展重金属现场实时便携检测提供了新途径和新思路。