State Key Laboratory of Bioelectronics, Southeast University, Nanjing, 210096, China.
Nanoscale. 2012 Sep 28;4(19):5998-6003. doi: 10.1039/c2nr31601c. Epub 2012 Aug 31.
We have developed a robust method for the visual detection of heavy metal ions (such as Hg(2+) and Pb(2+)) by using aptamer-functionalized colloidal photonic crystal hydrogel (CPCH) films. The CPCHs were derived from a colloidal crystal array of monodisperse silica nanoparticles, which were polymerized within the polyacrylamide hydrogel. The heavy metal ion-responsive aptamers were then cross-linked in the hydrogel network. During detection, the specific binding of heavy metal ions and cross-linked single-stranded aptamers in the hydrogel network caused the hydrogel to shrink, which was detected as a corresponding blue shift in the Bragg diffraction peak position of the CPCHs. The shift value could be used to estimate, quantitatively, the amount of the target ion. It was demonstrated that our CPCH aptasensor could screen a wide concentration range of heavy metal ions with high selectivity and reversibility. In addition, these aptasensors could be rehydrated from dried gels for storage and aptamer protection. It is anticipated that our technology may also be used in the screening of a broad range of metal ions in food, drugs and the environment.
我们开发了一种稳健的方法，用于通过适配体功能化胶体光子晶体水凝胶（CPCH）薄膜来可视化检测重金属离子（如 Hg(2+) 和 Pb(2+)）。CPCH 来源于单分散二氧化硅纳米粒子的胶体晶体阵列，该阵列在聚丙烯酰胺水凝胶中聚合。然后将重金属离子响应性适配体交联在水凝胶网络中。在检测过程中，重金属离子与水凝胶网络中交联的单链适配体的特异性结合导致水凝胶收缩，这表现为 CPCH 的布拉格衍射峰位置的相应蓝移。通过该蓝移值可以定量估计目标离子的量。实验证明，我们的 CPCH 适体传感器可以高选择性和可逆性筛选广泛浓度范围的重金属离子。此外，这些适体传感器可以从干燥凝胶中重新水合以进行储存和适配体保护。预计我们的技术也可用于筛选食品、药物和环境中广泛的金属离子。
