Mukdasai Siriboon, Uppachai Pikaned, Srijaranai Supalax
Materials Chemistry Research Center, Department of Chemistry, Faculty of Science, Khon Kaen University Khon Kaen 40002 Thailand
Department of Applied Physics, Faculty of Engineering, Rajamangala University of Technology Isan Khon Kaen Campus Khon Kaen 40000 Thailand.
RSC Adv. 2019 Sep 11;9(49):28598-28608. doi: 10.1039/c9ra05642d. eCollection 2019 Sep 9.
Herein, a new colorimetric paper sensor based on the layer-by-layer assembled multilayers of a cationic surfactant, tetrabutylammonium bromide (TBABr), and an anionic surfactant, sodium dodecyl sulfate (SDS), modified on filter paper was developed for the determination of total antioxidant capacity (TAC). In this study, gallic acid (GA) was used as the antioxidant standard. The fabricated (TBABr/SDS)/PAD was loaded with Fe ions to obtain Fe/(TBABr/SDS)/PAD, exhibiting high selectivity for the detection of GA when compared with the case of other metal ions. The interaction between GA and the Fe/(TBABr/SDS)/PAD sensor occurred rapidly, and the colorimetric paper sensor changed from yellow to purple immediately. The quantitative detection of GA was enabled by taking an image using an ordinary smartphone and applying the ImageJ software based on the change in color. Under optimum conditions, a linear response was obtained between the change in the color of the sensor and the TAC value expressed in terms of gallic acid equivalents. The linear range was from 0.50 μM to 6.50 mM with the detection limit of 0.35 μM. The colorimetric paper sensor was applied to detect the TAC in three kinds of green tea and vegetable samples, which provided the good recoveries of 86.0-109.9%. The proposed sensor is simple, cheap, equipment-free, rapid and environmentally friendly. In addition, the colorimetric sensor Fe/(TBABr/SDS)/PAD has potential applicability for TAC detection in real food samples.
在此，开发了一种基于阳离子表面活性剂四丁基溴化铵（TBABr）和阴离子表面活性剂十二烷基硫酸钠（SDS）在滤纸上逐层组装多层膜的新型比色纸传感器，用于测定总抗氧化能力（TAC）。在本研究中，没食子酸（GA）用作抗氧化剂标准品。将制备的（TBABr/SDS）/PAD负载铁离子以获得Fe/（TBABr/SDS）/PAD，与其他金属离子的情况相比，其对GA的检测具有高选择性。GA与Fe/（TBABr/SDS）/PAD传感器之间的相互作用迅速发生，比色纸传感器立即从黄色变为紫色。通过使用普通智能手机拍摄图像并基于颜色变化应用ImageJ软件实现了GA的定量检测。在最佳条件下，传感器颜色变化与以没食子酸当量表示的TAC值之间获得线性响应。线性范围为0.50 μM至6.50 mM，检测限为0.35 μM。该比色纸传感器应用于检测三种绿茶和蔬菜样品中的TAC，回收率良好，为86.0 - 109.9%。所提出的传感器简单、便宜、无需设备、快速且环保。此外，比色传感器Fe/（TBABr/SDS）/PAD在实际食品样品中TAC检测方面具有潜在的适用性。
