Hierarchical triple-shelled porous hollow zinc oxide spheres wrapped in graphene oxide as efficient sensor material for simultaneous electrochemical determination of synthetic antioxidants in vegetable oil

Abstract

Hierarchical triple-shelled porous hollow zinc oxide spheres (ZnO TPHS) were conveniently synthesized via a hard template method. And the ZnO TPHS were then wrapped into graphene oxide (GO) nanosheets though electrostatic attraction after being amino-functionalized. The composition of ZnO TPHS@GO hybrid was determined using energy dispersive X-ray spectroscopic analysis, X-ray diffraction and Raman spectra. The morphology of ZnO TPHS@GO hybrid was comprised of ZnO nanoparticles and ultrathin GO nanosheets that were characterized with scanning electron microscopy and transmission electron microscopy. The porous hollow structure and intimate contact between ZnO TPHS and GO interfaces provided a large surface area and high electron transfer activity for synthetic antioxidants in an acidic electrolyte. Based on this, a novel electrochemical sensor for the simultaneous determination of tert-butylhydroquinone (TBHQ) and butylated hydroxyanisole (BHA) has been constructed using ZnO TPHS@GO as sensing material. Under optimal conditions, the developed sensor exhibited excellent electrochemical responses in the co-detection of TBHQ and BHA, with limits of detection of 0.137 and 0.0488μM (S/N=3), respectively. Besides, the selectivity, reproducibility and application in edible vegetable oil samples were also investigated. This study proposed a novel method of fabrication of metal oxide-decorated GO-based materials for the fabrication of sensitive electrochemical sensors that met the needs of food safety control.