Novel electrochemical nuclear factorkappa B biosensor via analyte-restrained peptide nucleic acid displacement reaction constructed on different gold nanoparticle-deposited carbon electrodes

In this paper an electrochemical biosensor for NF-κB based on analyte-restrained peptide nucleic acid (PNA) displacement reaction is proposed, which is obviously more suitable for DNA binding proteins’ detection compared with previous exonuclease cleavage methods. In our detection system, PNA probe is modified on gold nanoparticles (AuNPs) deposited carbon electrodes which could competitively conjugate with one strand of the designed dsDNA forming a PNA/DNA duplex. Methylene blue (MB), as electrochemical signal molecule, specifically inserts into PNA/DNA duplex significantly amplifying the electrochemical signal. When NF-κB is present in the detection system, it is able to be recognized and bound with dsDNA against PNA restraining the formation of PNA/DNA duplex, thus the electrochemical signal responding to the decrease of PNA/DNA duplex could be used to analyze the concentration of NF-κB. Then, detection performances based on two different carbon electrodes, glassy carbon electrode (GCE) and screen-printed carbon electrode (SPCE), are compared. The portable SPCE with a better analysis performance has a low detection limit at 2.7 pg mL−1, which is more suitable for determining NF-κB in S. uberis-infected MECs sample. Benefit from commercialized mass production, it holds promising prospect in practical application in studying NF-κB-associated signal pathways and diagnosing inflammatory related diseases.