Embedded ZnO nanorod in ZIF-8 as a high-efficiency core-shell structural electrocatalyst for subnanomole level sensing of diethylstilbestrol

In view of the core-shell nanocomposites can complement the functions of the core and shell components, we here demonstrate a facile self-template strategy for synthesizing a one-dimensional rodlike hierarchical ZnO@ZIF-8 core-shell structure composed of a stabilized core and an active shell. The ZnO nanorods not only served as the template, but also as source of Zn ions for the in situ formation of ZIF-8 crystal shell, and the well-stabilized ZnO core preserved its own nature during the growth of the ZIF-8 shell. Furthermore, a sensing platform using ZnO@ZIF-8 as electrocatalyst was developed, which demonstrated salient electrocatalytic activity for diethylstilbestrol (DES) oxidation. The concentration of DES was directly proportional to its anodic peak current in the range of 2 nM-2 μM, and ultralow detection limit of 0.73 nM (S/N = 3) was achieved. The proposed method also gave excellent selectivity, reproducibility, and stability, showing promising analytical performance for the measurement of DES in food samples of animal origin.