3D hierarchical graphene oxide-Co LDHs composite, as a suitable platform for sensitive detecting carcinogenic...

Tert-butylhydroquinone (TBHQ) is a common food antioxidant widely applied to prolong the shelf life of food products, and its dosage must be stringently regulated to guarantee food safety. Herein, a sensitive electrochemical sensor was successfully constructed based on cobalt layered double hydroxide nanosheets anchored on graphene oxide (GO/Co LDHs). A three-dimensional (3D) hierarchical GO/Co LDHs composite with sandwich-stacked structure was fabricated through a facile one-step hydrothermal strategy. The surface morphology, elemental composition and crystal structure of GO/Co LDHs composite were systematically characterized via scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) were employed to investigate the electrocatalytic behavior of the GO/Co LDHs composite toward TBHQ detection. The excellent sensing performance of the fabricated sensor originates from the synergistic effect between the large conductive skeleton of graphene oxide and the abundant electrochemically active sites of Co LDHs. The proposed electrochemical sensor achieved a broad linear detection range of 0.01-220 μM for TBHQ with an ultra-low limit of detection (LOD) of 2.0 nM. Real-sample testing verified that the sensor possesses satisfactory recovery rates ranging from 94.8% to 103.9%. Moreover, the sensor maintained over 91.17% of its original sensing signal after 27 days of storage, demonstrating prominent long-term stability and great application prospects in practical food safety monitoring. In addition, the sensor exhibited superior repeatability, reproducibility and anti-interference capability, which made it a reliable platform for the sensitive determination of TBHQ in complex food matrices.