State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, People's Republic of China.
Mikrochim Acta. 2020 Aug 1;187(8):476. doi: 10.1007/s00604-020-04456-8.
A low-angle-dependent photonic crystal hydrogel (LAD-PCH) material was developed to simultaneously detect and remove uranyl ions (UO). Different from traditional SiO photonic crystal hydrogel with the problem of angle dependency, the LAD-PCH material overcomes the restriction of observation direction. The LAD-PCH is a composite material with the photonic crystal array of 180-nm monodisperse CdS@SiO particles embedded into the functional hydrogel. As one UO can bind to multiple carboxyl groups and amide groups, the functional hydrogel fabricated by acrylic acid and acrylamide will shrink after chelating. These changes in the hydrogel volume alter the array spacing and trigger a blue shift of diffraction wavelength and naked-eye visual color changes of LAD-PCH. The color can vary from orange-red to orange, yellow, green, and cyan, corresponding to the determination range of 100 pM-100 μM. The LAD-PCH material detects UO sensitively as the lowest detectable concentration is about 100 pM, and removes UO high-efficiently as the maximum adsorption capacity of U(VI) is about 1010 mg g at 298 K. This LAD-PCH material is convenient and has potential to simultaneously monitor and remove UO from uranium-polluted water. Schematic representation of the low-angle-dependent photonic crystal hydrogel (LAD-PCH) material for UO detection and removal: The structural colors of LAD-PCH material overcome the restriction of observation angles. After the ligands complex with UO, the networks of LAD-PCH show different degrees of shrinkage; these volume changes of hydrogel trigger obvious naked-eye visual color changes of LAD-PCH.
一种低角度依赖型光子晶体水凝胶（LAD-PCH）材料被开发出来，用于同时检测和去除铀酰离子（UO）。与传统的具有角度依赖性问题的 SiO 光子晶体水凝胶不同，LAD-PCH 材料克服了观察方向的限制。LAD-PCH 是一种复合材料，其光子晶体阵列由嵌入功能水凝胶中的 180nm 单分散 CdS@SiO 颗粒组成。由于一个 UO 可以与多个羧基和酰胺基结合，因此由丙烯酸和丙烯酰胺制成的功能水凝胶在螯合后会收缩。这些水凝胶体积的变化改变了阵列间距，并引发衍射波长的蓝移和 LAD-PCH 的裸眼视觉颜色变化。颜色可以从橙红色变为橙色、黄色、绿色和青色，对应于 100pM-100μM 的测定范围。LAD-PCH 材料对 UO 的检测具有高灵敏度，最低检测浓度约为 100pM，对 UO 的去除效率高，在 298K 时 U(VI)的最大吸附容量约为 1010mg g。这种 LAD-PCH 材料方便且具有从铀污染水中同时监测和去除 UO 的潜力。UO 检测和去除用低角度依赖型光子晶体水凝胶（LAD-PCH）材料的示意图：LAD-PCH 材料的结构颜色克服了观察角度的限制。配体与 UO 络合后，LAD-PCH 的网络会发生不同程度的收缩；这些水凝胶体积的变化会引发 LAD-PCH 明显的裸眼视觉颜色变化。
