Polymer Vesicle Sensor for Visual and Sensitive Detection of SO2 in Water

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• 作者：Tong Huang ; Zhilin Hou ; Qingsong Xu ; Lei Huang ; Chuanlong Li ; Yongfeng Zhou
• 刊名：Langmuir
• 出版年：2017
• 出版时间：January 10, 2017
• 年：2017
• 卷：33
• 期：1
• 页码：340-346
• 全文大小：448K
• ISSN：1520-5827

文摘

This study reports the first polymer vesicle sensor for the visual detection of SO₂ and its derivatives in water. A strong binding ability between tertiary alkanolamines and SO₂ has been used as the driving force for the detection by the graft of tertiary amine alcohol (TAA) groups onto an amphiphilic hyperbranched multiarm polymer, which can self-assemble into vesicles with enriched TAA groups on the surface. The polymer vesicles will undergo proton exchange with cresol red (CR) to produce CR-immobilized vesicles (CR@vesicles). Subsequently, through competitive binding with the TAA groups between CR and SO₂ or HSO₃^–, the CR@vesicles (purple) can quickly change into SO₂@vesicles (colorless) with the release of protonated CR (yellow). Such a fast purple to yellow transition in the solution allows the visual detection of SO₂ or its derivatives in water by the naked eye. A visual test paper for SO₂ gas has also been demonstrated by the adsorption of CR@vesicles onto paper. Meanwhile, the detection limit of CR@vesicles for HSO₃^– is approximately 25 nM, which is improved by approximately 30 times when compared with that of small molecule-based sensors with a similar structure (0.83 μM). Such an enhanced detection sensitivity should be related to the enrichment of TAA groups as well as the CR in CR@vesicles. In addition, the CR@vesicle sensors also show selectivity and specificity for the detection of SO₂ or HSO₃^– among anions such as F^–, Br^–, Cl^–, SO₄^2–, NO₂^–, C₂O₄^2–, S₂O₃^2–, SCN^–, AcO^–, SO₃^2–, S^2–, and HCO₃^–.