In summary, taking advantage of a GO fluorescence switchbased
MGHP, we developed a simple, label-free, enzyme-free and
sensitive new fluorescent strategy for the detection of NF-κB p50.
Compared with the fluorescent strategies mentioned above, it
displayed some unique and attractive characteristics: (i) The
MGHP was firstly introduced into the detection of TFs and showed
multiple functions, including adsorption onto the GO surface, recognizing
targets and carrying the signal carrier. This MGHP did
not need complicated sequence design or any fluorescent labeling,
which made it more simple and cost-effective. (ii) Due to no requirement
of any enzyme, the false positives caused by non-specific
protein binding and the negative effect of the endogenous
nuclease in the real samples could be eliminated. (iii) The GO
fluorescence switch used here guaranteed a high signal-to-noise
ratio. (iv) This strategy was potentially universal because this
MGHP could be easily designed for other targets by changing the
corresponding recognition sequences. Moreover, this proposed
strategy achieved sensitive detection for purified NF-κB p50 and
HeLa cell nuclear extracts with LOD of 0.2 nM and 7.8 ng/mL, respectively.
In addition, it could be used to screen inhibitors of NF-
κB p50 activity. Finally, the proposed strategy might offer a new
potential approach for reliable quantification of TFs in clinical diagnostics
and treatment research of some diseases.