Controllable gold nanoparticle deposition on carbon nanotubes and their application in immunosensing

Abstract

A CNT–AuNPs hybrid nanocomposite platform was prepared from nanodisperse AuNPs in N-[3-(trimethoxysilyl)propyl]ethylenediamine (EDAS) sol–gel matrices with purified MWCNT. EDAS, an amine group-containing sol–gel solution, was utilized for its ability to stabilize the nanoparticles in solution. The developed model system was based on immobilized rabbit anti-mouse IgG-HRP (horseradish peroxidase) for reagentless detection of mouse IgG. The immunosensing platform was prepared by using Nafion for the immobilization of rabbit anti-mouse IgG-HRP and CNT–AuNPs hybrid nanocomposite on a glassy carbon electrode used for the detection of mouse IgG which provides a biocompatible microenvironment. The resulting CNT–AuNPs nanocomposite brings new capabilities for electrochemical devices by using the synergistic action of its electrocatalytic activity. The CNT–AuNPs were characterized using SEM, TEM, EIS, and AFM, and the analytical performance was monitored by differential pulse voltammetry. The detection limit of mouse IgG is 0.5 ng mL⁻¹ (S/N ratio = 3). In addition, the immunosensor efficiently allowed a specific electrochemical analysis of mouse IgG and easy discrimination of goat IgG, chicken IgG, and rabbit IgG.