Flower-like molecularly imprinted nanocomposite based on ZnO@Au for sensitive and selective electrochemical sensing of tert-butylhydroquinone

A novel strategy based on flower-like nanocomposite combined with molecularly imprinted polymers (MIP) was developed to achieve electrochemical sensing toward tert-butylhydroquinone (TBHQ) with high sensitivity and selectivity. The flower-like nanocomposite of gold nanoparticles functionalized zinc oxide nanoflowers (ZnO@Au NFs) was prepared by one-step in-situ reduction of gold nanoparticles on the exterior of zinc oxide nanoflowers. Subsequently, the electrodeposition of MIP was taken place on the surface of three-dimensional ZnO@Au NFs in the presence of monomer pyrrole and template molecule TBHQ by cyclic voltammetry, and the morphology of imprinted films could be clearly observed by scanning electron microscopy (SEM). The nanocomposite of ZnO@Au NFs provided a specific surface area of 9.94 m²/g for MIP electrodepositing due to a good deal of three-dimensional petal-like structures. More importantly, the obtained flower-like MIP nanocomposite increased the electroactive area and promoted the electrical signal when TBHQ was oxidized in the imprinted cavities, which significantly improved the sensitivity and selectivity for TBHQ determination. Under the optimal conditions, the proposed sensor was able to determine TBHQ within a broad linear range from 0.5 to 200 μM, with a detection limit as low as 58 nM. Besides, the practicability of this sensor was validated in real samples, obtaining well-pleasing recoveries from 95.0 % to 106.6 %. This flower-like MIP-based electrochemical sensor showed high sensitivity, good specificity and acceptable reproducibility, providing a promising platform for highly sensitive sensing of TBHQ.