Electrochemical biosensor for the nuclear factor kappa B using a gold nanoparticle-assisted dual signal amplification method

Nuclear factor kappa B (NF-κB) is a transcription factor that plays a central role in the signaling pathway and network of gene regulation. The dysregulation of NF-κB signaling has been implicated in the pathogenesis of a number of diseases. We report on a dual amplification strategy for the highly sensitive electrochemical sensing of NF-κB by means of a nicking endonuclease-assisted amplification reaction (NEAR). The quantity of the DNA obtained is subsequently determined by applying a gold nanoparticle-assisted electrochemical amplification step. This represents the first example of a combination of NEAR and a dual amplification strategy for the detection of a transcription factor. Experimental results show that the electrochemical signal generated by the redox probe (the ruthenium(III) hexammine complex) can be related to the concentration of NF-κB. The response of the electrode is linearly related to the concentration of NF-κB in the 100 pM to 10 nM range, with a detection limit as low as 80 pM. (author)