College of Materials Science & Engineering, South China University of Technology, Guangzhou 510640, China.
Langmuir. 2010 Mar 16;26(6):4529-34. doi: 10.1021/la9033244.
Heightened concern for human health and environmental protection has stimulated active research on the potential impact of transition-metal ions and their toxic effects, thus it is very demanding to design transition-metal ion detection methods that are cost-effective, rapid, facile, and applicable to the environmental and biological milieus. In this study, we demonstrated an alternative strategy for constructing a water-soluble FRET-based ratiometric sensor for ferric ion detection by forming a supramolecular beta-cyclodextrin/dye complex. This water-soluble FRET system consists of a dansyl-linked beta-cyclodextrin (beta-CD-DNS) and a spirolactam rhodamine-linked adamantane (AD-SRhB). The dansyl moiety serves as the donor, and the spirolactam-rhodamine B derivative (SRhB) was chosen as a sensitive, selective chemosensor for Fe(III) ions and a very efficient ring-opening reaction induced by Fe(III) generates the long-wavelength rhodamine B fluorophore that can act as the energy acceptor. Moreover, the adamantyl (AD) group, which is known for its capability to form stable host-guest inclusion complexes with beta-CD derivatives, was covalently linked to the spirolactam rhodamine, thus the adamantyl moiety of the ion-recognition element can be anchored inside the CD cavity. In this way, the donor-acceptor separation can be kept within the critical Forster distance; accordingly, energy transfer can take place from the donor (dansyl) to the acceptor (rhodamine derivative/Fe(III) complex), and thus ratiometric detection for Fe(III) in an aqueous medium can be fulfilled. This FRET-based supramolecular sensor can be readily formed via an inclusion process using the donor part and the acceptor part, hence this strategy could afford a robust approach for constructing a wide range of FRET-based water-soluble sensing systems simply by assembling a specifically predesigned donor-linked CD and acceptor-linked adamantane.
高度关注人类健康和环境保护，刺激了对过渡金属离子及其毒性影响的潜在影响的积极研究，因此非常需要设计具有成本效益，快速，简便且适用于环境和生物环境的过渡金属离子检测方法。在这项研究中，我们通过形成超分子β-环糊精/染料复合物，展示了一种用于检测铁离子的水溶性 FRET 比率传感器的替代构建策略。这种水溶性 FRET 系统由丹磺酰基连接的β-环糊精（β-CD-DNS）和螺环缩酮罗丹明连接的金刚烷（AD-SRhB）组成。丹磺酰基部分作为供体，螺环缩酮罗丹明 B 衍生物（SRhB）被选为对 Fe（III）离子具有高灵敏度和选择性的化学传感器，并且 Fe（III）诱导的螺环开环反应生成长波长罗丹明 B 荧光团，可以充当能量受体。此外，金刚烷基（AD）基团以其与β-CD 衍生物形成稳定的主客体包合络合物的能力而闻名，被共价连接到螺环缩酮罗丹明上，因此离子识别元件的金刚烷基部分可以锚定在 CD 腔体内。这样，供体-受体分离可以保持在临界 Förster 距离内；因此，可以从供体（丹磺酰基）向受体（罗丹明衍生物/Fe（III）络合物）发生能量转移，从而可以在水介质中实现对 Fe（III）的比率检测。这种基于 FRET 的超分子传感器可以通过包含过程很容易地形成，该过程使用供体部分和受体部分，因此该策略可以通过组装特定设计的供体连接的 CD 和受体连接的金刚烷来提供构建广泛的基于 FRET 的水溶性传感系统的稳健方法。
