Regulating the hydrothermal synthesis of ZnO nanorods to optimize the performance of spirally hierarchical structure-based glucose sensors

This paper reports the effects of the synthesizing parameters on the surface morphologies of ZnO nanorod-based spirally hierarchical structures and the performance of related spirally hierarchical structure-based glucose sensors. ZnO nanorods were hydrothermally synthesized on Au cylindrical spirals with 3 sets of the synthesizing parameters, and glucose oxidase (GOx) was immobilized on these ZnO nanorods, thus 3 batches of the spirally hierarchical structure-based glucose enzymatic electrodes were fabricated. Geometric, crystalline and electrochemical characterization indicates that of all 3 batches of the spirally hierarchical structures, those fabricated respectively at 25 mM Zn²⁺ concentration of the growth solution, for 1.5 h the growth duration, and at 0.5 mM Zn²⁺ concentration of the seed solution all have Gaussian random rough surfaces. This gives rise to the largest surface area of the related spirally hierarchical structure, the most effective GOx immobilization of the corresponding enzymatic electrode, and the optimal performance of the related glucose sensor. The results benefit not only the batch construction but also the standardization of other hierarchical structure-based glucose sensors.