An electrochemiluminescence biosensor for p53 antibody based on Zn-MOF/GO nanocomposite and Ag+-DNA amplification

An ultrasensitive electrochemiluminescence biosensor was established based on the Zn-MOF/GO nanocomposite. Ag(I)-embedded DNA complexes were used as a signal amplification reagent. In this work, 5,10,15,20 tetrakis(4-carboxyphenyl)porphyrin (TCPP) and Zn2+ were integrated into a porphyrin paddlewheel framework (Zn-MOF) by a hydrothermal method. The synthesized Zn-MOF material has electrochemiluminescence property, and the luminescence intensity is improved after being composited with graphene oxide (GO). Based on the composite material, we constructed an ultrasensitive ECL biosensor for the p53 antibody detection. The composite material acted as an admirable substrate and then loaded plenty of p53 antigens to recognize the target (p53 antibody) accurately. Because of the bridging effect of streptavidin and biotin-conjugated goat anti-rabbit IgG (bio-ab2), the rich-C DNA with positive correlation with the target was modified on the electrode and then captured the co-reactant accelerator Ag+ to amplify the signal. Therefore, the ECL biosensor response increases with increasing p53 antibody concentration. In the range 0.1 fg/mL-0.01 ng/mL, the response signal of the biosensor has a good linear relationship with the p53 antibody concentration. The detection limit is 0.03 fg/mL (S/N = 3). Impressively, the biosensor not only featured high sensitivity, good stability, and excellent specificity for the detection of p53 antibody, but also provides a new way for early detection of cancer.