The controlling and monitoring of blood glucose are very important for diabetes patients. We present highly sensitive non-enzymatic electrodes for glucose electrochemical detection based on gold nanoparticles (Au-NPs) decorated zinc oxide nanorods (ZnO-NRs). We prepared ZnO seed layer on ITO/glass substrate and synthesis ZnO-NRs structure by hydrothermal growth technique. A label-free electrode for glucose detection was successfully accomplished by functionalizing Au-NPs on ZnO-NRs. By controlling the Au-NPs density along the ZnO-NRs, the electrode exhibit high sensitivity (157.34 μA cm −2 mM −1 ) with wide range (0.5-10 mM), low limit of detection (0.055 mM), with excellent stability and repeatability. Moreover, the interference effect of the other molecules such as ascorbic acid (AA) and uric acid (UA) was investigated. Our results illustrate that the present electrode is suitable for glucose detection in human blood samples.

The morphological properties, e.g. diameter, aspect ratio, and density, of zinc oxide nanorods (ZnO-NRs) can be achieved through the control of seeding film morphology in seed-assisted hydrothermal process. The different morphologies of seeding film made by aluminum-doped zinc oxide (AZO) thin films are obtained by varying the thickness of seeding film. The change of seeding morphology from small granules with (002) plane dominant to platelets with (103) plane dominant leads to the significant change in the morphological formation of ZnO-NRs successively grown on the seeding film. The seeding film containing the dominant plane of (002) and small granules offers vertical-aligned ZnO-NRs with high surface area (high density and respect ratio) attributed to high nucleating density as well as the limit of the lateral growth from the surrounding adjacent nanorods. This work provides the consideration of morphological properties of seeding film.

Photoelectrochemical (PEC) activity is possibly enhanced by an increase in photocurrent generated from the photoanode. In this work, a modified photoanode that consists of zinc oxide nanorods (ZnO-NRs) decorated with gold nanoparticles (Au-NPs) is proposed to improve the generation of photocurrent. X-ray diffraction and scanning electron microscopy are employed to confirm the decoration of Au-NPs on well-aligned ZnO-NRs. A significant enhancement (∼4 times) in photocurrent density is obtained from the ZnO-NR photoanode decorated with Au-NPs compared to the bare ZnO-NR photoanode. Photoluminescence and UV-visible spectroscopy reveal that the improvement in photocurrent density results from (i) the decrease in charge recombination in the ZnO-NRs due to charge dissociation and (ii) the additional injection of charge from Au-NPs owing to localized surface plasmon resonance. This research presents the idea of taking the benefit from Au-NPs to enhance the photocurrent density in PEC applications through the decrease in charge recombination and the increase in charge injection.