基于茶多酚与三价铁的络合性以及对氧化铈的还原性,构建了交叉响应的液体阵列传感器,为茶叶种类的区分提供了一种新方法.利用水热法合成了硅酸锌空心微球和纳米棒作为三价铁的吸附剂,同时合成了可被茶多酚还原的纳米氧化铈,以硅酸锌-硫氰酸铁和氧化铈共同构建3×3阵列.对5种茶多酚和14种茶叶进行了检测,每个样本做5次平行实验,通过聚类分析(HCA)和主成份分析(PCA)方法对反应前后的图谱进行了分析.结果表明,该阵列能够将结构类似的茶多酚化合物准确区分,并且平行样本之间稳定性较好;同时对不同品种的茶叶样本区分效果良好,结合反应前后的差谱图可以实现对茶叶的定性分析.该方法在茶叶品质和食品质量的快速可视化检测方面具有潜在应用价值.
A liquid colorimetric sensor array was presented for cross-reactive discrimination of tea fusions based on complexation reaction and redox reaction of tea polyphenols with ferric ions and ceria nanoparticles,respectively. Hydrothermal reaction was applied to synthesize different kinds of ceria nanoparticles,hollow nanospheres and nanorods of zinc silicate to immobilized ferric thiocyanate[Fe( SCN)_3],which were subsequently combined to construct a 3×3 colorimetric sensor array. Performance of the colorimetric sensor array was evaluated using 5 kinds of tea polyphenols and 14 kinds of tea fusions with 5 repeated parallels. Hierarchical clustering analysis( HCA) and principal component analysis( PCA) of the colorimetric profiles suggested that all 5 kinds of tea polyphenols can be easily differentiated with good reproducibility. Correct discrimination of 14 kinds of tea fusions was also realized according to individual quality grade and categories. Our preliminary study provides a potential alternative for fast visible detection and discrimination of teas within different qualities and grades.