A Non‐Enzymatic Hydrogen Peroxide Sensor Based on Gold Nanoparticles/Carbon Nanotube/Self‐Doped Polyaniline Hollow Spheres

In this study, a novel non‐enzymatic hydrogen peroxide (H 2 O 2 ) sensor was fabricated based on gold nanoparticles/carbon nanotube/self‐doped polyaniline (AuNPs/CNTs/SPAN) hollow spheres modified glassy carbon electrode (GCE). SPAN was in‐site polymerized on the surface of SiO 2 template, then AuNPs and CNTs were decorated by electrostatic absorption via poly(diallyldimethylammonium chloride). After the SiO 2 cores were removed, hollow AuNPs/CNTs/SPAN spheres were obtained and characterized by transmission electron microscopy (TEM), field‐emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR). The electrochemical catalytic performance of the hollow AuNPs/CNTs/SPAN/GCE for H 2 O 2 detection was evaluated by cyclic voltammetry (CV) and chronoamperometry. Using chronoamperometric method at a constant potential of −0.1 V (vs. SCE), the H 2 O 2 sensor displays two linear ranges: one from 5 µM to 0.225 mM with a sensitivity of 499.82 µA mM −1  cm −2 ; another from 0.225 mM to 8.825 mM with a sensitivity of 152.29 µA mM −1  cm −2 . The detection limit was estimated as 0.4 µM (signal‐to‐noise ratio of 3). The hollow AuNPs/CNTs/SPAN/GCE also demonstrated excellent stability and selectivity against interferences from other electroactive species. The sensor was further applied to determine H 2 O 2 in disinfectant real samples.