The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China.
Molecules. 2014 Jun 6;19(6):7459-79. doi: 10.3390/molecules19067459.
In this study, a label-free graphene-based fluorescence probe used for detection of volatile organic liquids was fabricated by a simple, efficient and low-cost method. To fabricate the probe, a bio-based β-cyclodextrin (β-CD) was firstly grafted on reduced graphene surfaces effectively and uniformly, as evidenced by various characterization techniques such as Ultraviolet/Visible spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, scanning electron microscopy and transmission electron microscopy. The subsequent inclusion of Rhodamine B (RhB) into the inner cavities of the β-CD grafted on the graphene surfaces was achieved easily by a solution mixing method, which yielded the graphene-based fluorescent switch-on probe. In addition, the gradual and controllable quenching of RhB by Fluorescence Resonance Energy Transfer from RhB to graphene during the process of stepwise accommodation of the RhB molecules into the β-CD-functionalized graphene was investigated in depth. A wide range of organic solvents was examined using the as-fabricated fluorescence probe, which revealed the highest sensitivity to tetrahydrofuran with the detection limit of about 1.7 μg/mL. Some insight into the mechanism of the different responsive behaviors of the fluorescence sensor to the examined targets was also described.
在这项研究中，通过一种简单、高效和低成本的方法制备了一种基于石墨烯的无标记荧光探针，用于检测挥发性有机液体。为了制备探针，首先将生物基 β-环糊精（β-CD）有效地、均匀地接枝到还原氧化石墨烯表面，这可以通过各种表征技术得到证明，如紫外/可见光谱、傅里叶变换红外光谱、X 射线衍射、热重分析、扫描电子显微镜和透射电子显微镜。随后，通过溶液混合法将罗丹明 B（RhB）很容易地包合到接枝在石墨烯表面的β-CD 的内腔中，从而得到基于石墨烯的荧光开启探针。此外，在 RhB 分子逐步容纳到β-CD 功能化的石墨烯的过程中，通过 RhB 到石墨烯的荧光共振能量转移，深入研究了 RhB 的逐渐和可控猝灭。使用所制备的荧光探针对多种有机溶剂进行了测试，结果表明，该探针对四氢呋喃的灵敏度最高，检测限约为 1.7μg/mL。还描述了荧光传感器对所检测目标的不同响应行为的机制的一些见解。
