State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, Department of Polymer Science and Engineering, College of Chemistry, Chemical Engineering and Materials Science , Soochow University , Suzhou , Jiangsu 215123 , P. R. China.
ACS Appl Mater Interfaces. 2018 Mar 7;10(9):8287-8295. doi: 10.1021/acsami.8b00164. Epub 2018 Feb 26.
Developing effective methods for detecting illegal additives in food or seasoning is of great significance. In this study, a sensing strategy for selective detection of Sudan dyes was designed based on the fluorescence inner-filter effect (IFE) by using poly(phenylenevinylene) (PPV) solid materials in combination with an optimized experimental protocol. Two types of fluorescent solid materials, electrospun fibrous membranes and drop-cast films, were fabricated with PPV as the fluorophore and poly(vinyl alcohol) as the matrix, respectively. Sudan dyes greatly quenched the fluorescence of the membrane and film, whereas other food colorings or possible food ingredients displayed a much smaller or negligible quenching effect. The sensing mechanism was studied, and the selectivity was ascribed to IFE, which requires the overlap between the absorption of the analyte and absorption/emission of the sensing material. The form of materials (membrane or film), the content of PPV, and the cross-linking process did not have much influence on the selectivity and sensitivity, which is consistent with the IFE mechanism and demonstrates the advantage of not requiring strict control of the preparative process. All the cross-linked materials were found to be stable against water/humidity and displayed good reversibility in sensing and can be reused at least for 10 cycles with negligible influence on the sensing performance. A cross-linked membrane was selected for detecting Sudan dyes in chili powder because folding did not affect the mechanical stability of the membrane. Two different protocols were used to pretreat the chili samples, which allowed the detection of Sudan dyes in chili powder as well as the discrimination of Sudan dyes from synthetic food coloring such as allura red. This study provides a facile and cost-effective method for preparing reusable sensing materials for detecting some dyes in commercial foods or food seasonings.
开发用于检测食品或调味料中非法添加剂的有效方法具有重要意义。在本研究中，设计了一种基于荧光内滤效应（IFE）的苏丹染料选择性检测传感策略，该策略结合了优化的实验方案，使用聚对苯乙烯（PPV）固体材料。制备了两种荧光固体材料，即电纺纤维膜和滴铸薄膜，分别以 PPV 为荧光团，以聚乙烯醇（PVA）为基质。苏丹染料大大猝灭了膜和膜的荧光，而其他食用色素或可能的食品成分则显示出较小或可忽略的猝灭效应。研究了传感机制，选择性归因于IFE，IFE 需要分析物的吸收与传感材料的吸收/发射之间的重叠。材料的形式（膜或膜）、PPV 的含量和交联过程对选择性和灵敏度没有太大影响，这与IFE 机制一致，并证明了不需要严格控制制备过程的优势。所有交联材料都被发现对水/湿度稳定，并且在传感中具有良好的可逆性，至少可以重复使用 10 次，而对传感性能的影响可以忽略不计。选择交联膜用于检测辣椒粉中的苏丹染料，因为折叠不会影响膜的机械稳定性。使用两种不同的方案预处理辣椒样品，这允许在辣椒粉中检测苏丹染料，并区分苏丹染料和合成食用色素，如诱惑红。本研究提供了一种简便且经济有效的方法，用于制备可重复使用的传感材料，用于检测商业食品或调味料中的某些染料。
