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 (H₂O₂) 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 SiO₂ template, then AuNPs and CNTs were decorated by electrostatic absorption via poly(diallyldimethylammonium chloride). After the SiO₂ 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 H₂O₂ detection was evaluated by cyclic voltammetry (CV) and chronoamperometry. Using chronoamperometric method at a constant potential of -0.1V (vs. SCE), the H₂O₂ sensor displays two linear ranges: one from 5μM to 0.225mM with a sensitivity of 499.82μAmM^-1cm^-2; another from 0.225mM to 8.825mM with a sensitivity of 152.29μAmM^-1cm^-2. The detection limit was estimated as 0.4μM (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 H₂O₂ in disinfectant real samples.