Functional electrospun nanofibers-based electrochemiluminescence immunosensor for detection of the TSP 53 using RuAg/SiO 2 NPs as signal enhancers.

A functional electrospun nanofibers-based electrochemiluminescence (ECL) immunosensor for detection of the tumor suppressor protein p53 (TSP53 ) at trace level using core-shell nanocomposite as signal enhancers is fabricated. The gold nanoparticles (AuNPs) were decorated on the surface of the electrospun carbon-nanotubes (MWCNTs) doped chitosan (CTS) nanofibers (MWCNTs-CTS) by in-situ electrodeposition. The functional electrospun nanofibers (MWCNTs-CTS-AuNPs) was utilized as supporting scaffolds for TSP53 capture antibody (CAb ) immobilization firstly. They can dramatically increase the amount and stability of CAb attachment, and efficiently enhance the sensitivity of detection. After a sandwich immunoreaction, TSP53 and Ru(bpy)3 2+ /silver nanoparticles doped silica core-shell nanocomposite (RuAg/SiO2 NPs)-labeled detection antibody (RuAg/SiO2 NPs@DAb ) captured onto the electrode surface. It was observed that the increase of response ECL signal was proportional to the TSP53 concentration in the range of 1 pg mL-1 to 1 ng mL-1 . The detection limit was 0.5 pg mL-1 , which is comparable or better than that in reported TSP53 assays. The immunosensor was successfully applied to determination of TSP53 in normal human cubital vein blood samples with good recovery, and the results are basically consistent with the TSP53 Kit (ELISA). Excellent sensitivity and selectivity make the developed ECL immunosensor a potential and simple tool for the detection of tumor biomarkers.