Functional electrospun nanofibers-based electrochemiluminescence immunosensor for detection of the TSP53 using RuAg/SiO2NPs as signal enhancers

Abstract

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 (C_Ab) immobilization firstly. They can dramatically increase the amount and stability of C_Ab attachment, and efficiently enhance the sensitivity of detection. After a sandwich immunoreaction, TSP₅₃ and Ru(bpy)₃²⁺/silver nanoparticles doped silica core-shell nanocomposite (RuAg/SiO₂NPs)-labeled detection antibody (RuAg/SiO₂NPs@D_Ab) 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.

Keywords: Core-shell nanocomposite; Electrochemiluminescence immunosensor; Electrospun nanofibers; Sandwich immunoreaction; Tumor suppressor protein p53.