title: Label-free and enzyme-free detection of transcription factors with graphene oxide fluorescence switch-based multifunctional G-quadruplex-hairpin probe.
abstract: Transcription factors (TFs) play pivotal roles in the regulation of a variety of essential cellular processes and some of them have been recognized as potential diagnostic markers and therapeutic targets of some diseases. Sensitive and accurate detection of TFs is of great importance to better understanding their roles in gene regulation and evaluation of disease state. Here, we developed a simple, label-free and enzyme-free new fluorescent strategy for the detection of TFs by graphene oxide (GO) fluorescence switch-based multifunctional G-quadruplex-hairpin probe (MGHP). The MGHP possessed of three functions simultaneously, adsorbing onto GO with the loop part, binding to target with the stem part and serving as signal carrier with the terminal G-quadruplex. First, the MGHP was adsorbed quickly to GO. Next, the TF bound to the stem part of MGHP to form a huge target-MGHP complex, which led to desorption of the complex from GO. Finally, NMM was inserted into G-quadruplex in the complex to yield an enhanced fluorescence response. The GO used here, as a fluorescence switch, could quickly and efficiently quench the fluorescence of NMM inserted into the MGHP absorbed on the GO, guaranteeing a high signal-to-noise ratio. Sensitive detection of purified NF-κB p50 and HeLa cell nuclear extracts were achieved with detection limits of 0.2nM and 7.8ng/µL, respectively. Moreover, this proposed strategy could be used to screen inhibitors of NF-κB p50 activity. The strategy proposed here might offer a new potential approach for reliable quantification of TFs in clinical diagnostics and treatment research of some diseases.
authors: Key Laboratory for Colloid and Interface Chemistry of Education Ministry, School of Chemistry and Chemical Engineering, Shandong University, 250100 Jinan, PR China.
authors: Desong
authors: D
authors: Zhu
authors: School of Pharmaceutical Sciences, Shandong University, 250012 Jinan, PR China.
authors: Lei
authors: L
authors: Wang
authors: Key Laboratory for Colloid and Interface Chemistry of Education Ministry, School of Chemistry and Chemical Engineering, Shandong University, 250100 Jinan, PR China.
authors: Xiaowen
authors: X
authors: Xu
authors: Key Laboratory for Colloid and Interface Chemistry of Education Ministry, School of Chemistry and Chemical Engineering, Shandong University, 250100 Jinan, PR China. Electronic address: wjiang@sdu.edu.cn.
authors: Wei
authors: W
authors: Jiang
mesh_terms: D015374:Biosensing Techniques; D005456:Fluorescent Dyes / Q000737:chemistry; D054856:G-Quadruplexes; D006108:Graphite / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D052002:NF-kappa B p50 Subunit / Q000302:isolation & purification*; D010087:Oxides / Q000737:chemistry; D014157:Transcription Factors / Q000302:isolation & purification*
chemical_list: D005456:Fluorescent Dyes; D052002:NF-kappa B p50 Subunit; D010087:Oxides; D014157:Transcription Factors; D006108:Graphite
keywords: Enzyme-free; Fluorescent detection; Graphene oxide; Label-free; Multifunctional G-quadruplex-hairpin probe; Transcription factors