Template-assisted synthesis of 3D ordered mesoporous graphitic carbon nitride decorated with gold nanoparticles for dopamine sensing

Abstract

Three-dimensional mesoporous graphitic carbon nitride (Au/3Dom CN) decorated with a gold nanoparticle composite was successfully prepared via a template-assisted method using Au–SiO₂ nanospheres as sacrificial agents. Combined characterization through X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) verified the successful fabrication of the Au/3Dom CN composite. Noteworthily, Au/3Dom CN displayed good sensing performance for the electrochemical detection of dopamine (DA) with a high selectivity of 15.23 μA mM⁻¹ and a relatively low detection limit of 0.02 μM (S/N = 3). Besides, the Au/3Dom CN composite exhibited an excellent anti-interference performance. These results reveal that the combined advantages of Au NPs and mesoporous g-C₃N₄ were conducive to the composite's sensing performance. Simultaneously, a mechanism was proposed to illustrate the good selectivity of the Au/3Dom CN composite for DA. This work presents a new avenue for dopamine detection using a mesoporous g-C₃N₄-based composite.