State Key Laboratory for Chemo/biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China.
Biosens Bioelectron. 2012 Apr 15;34(1):88-93. doi: 10.1016/j.bios.2012.01.023. Epub 2012 Jan 26.
A novel fluorescence biosensing strategy for simple, rapid and sensitive selecting quadruplex-binding ligands was reported by using graphene oxide (GO) as the fluorescence quencher. Data from transmission electron microscopy (TEM), atomic force microscopy (AFM) image, Fourier transform infrared (FT-IR) spectroscopy and Raman spectroscopy demonstrated that single-layered GO sheets were successfully prepared with well dispersion in aqueous solution. The fluorescein amidite (FAM)-labeled signal probe first adsorbed onto the surface of GO through π-stacking interaction between the ring structure in the nucleobases and the hexagonal cells of GO, and the fluorescence of the dye was quenched. When the quadruplex-binding ligands were introduced, the signal probe folded to form intramolecular G-quadruplex structure, which led to the releasing of FAM-labeled signal probe from the surface of GO and the fluorescence intensity recovered. Three series of Chinese medicine monomers were investigated by the proposed method, and the flavonoids were demonstrated to be the potential quadruplex-binding ligands by fluorescence measurement and melting temperature analysis. The results indicated that this strategy offers a simple, rapid and sensitive method for screening G-quadruplex ligands and it could find wide applications in the discovery of new antitumor drugs.
一种新型荧光生物传感策略，用于简单、快速和灵敏地选择四链体结合配体，通过使用氧化石墨烯 (GO) 作为荧光猝灭剂来实现。透射电子显微镜 (TEM)、原子力显微镜 (AFM) 图像、傅里叶变换红外 (FT-IR) 光谱和拉曼光谱的数据表明，成功制备了具有良好分散性的单层 GO 片。荧光素酰胺 (FAM) 标记的信号探针首先通过碱基环结构与 GO 的六方晶格之间的π-堆积相互作用吸附在 GO 表面，染料的荧光被猝灭。当引入四链体结合配体时，信号探针折叠形成分子内 G-四链体结构，导致 FAM 标记的信号探针从 GO 表面释放，荧光强度恢复。通过所提出的方法研究了三系列中药单体，荧光测量和熔点分析表明黄酮类化合物是潜在的四链体结合配体。结果表明，该策略为筛选 G-四链体配体提供了一种简单、快速和灵敏的方法，有望在新型抗肿瘤药物的发现中得到广泛应用。
