Gold nanoparticles modified Cu2O/ZnO nanorod arrays synthesized with anodic aluminum oxide template for high performance non-enzymatic glucose sensor

In this study, gold nanoparticles (Au NPs) modified cuprous oxide (Cu₂O) on zinc oxide nanorod arrays (ZnO NRAs) prepared by anodic aluminum oxide (AAO) template was used as heterogeneous sensing electrodes. Among them, the ZnO NRAs can increase the sensing contact area, and the localized surface plasmon resonance (LSPR) of Au NPs can gain sensing current and stability. First of all, the experiment was conducted to grow array-shaped holes on the evaporated aluminum film through anodizing treatment. To prepare a fully formed alumina template with the time needed of the 2nd anodization was 3, 4, and 5 min, respectively. Secondly, the technique of electroplating was employed to grow ZnO nanorods in array holes for 10 and 20 min, respectively, to prepare a transparent ZnO NRAs. Thirdly, Cu₂O films were electrodeposited on the surface of ZnO NRAs for 60, 90, and 120 s, respectively, considering the pH value from 8, 9, 10 to 11. Finally, chemically synthesized Au NPs were used and dispersed uniformly through Nafion and dropwise coated on Cu₂O/ZnO NRA/ITO to form a heterogeneous sensing electrode. The sensing electrodes were analyzed by the electrochemical measurement of its redox reaction characteristics, and the best sensitivity, linearity and fitting superiority were determined. It was found that there were two linear sections of high and low concentration. These experimental results indicate that the LSPR of Au NPs could increase the sensing slope from 25.10 to 29.52 μAmg⁻¹dL. The high and low concentration sensitivity increased from 958.41 & 320.03 to 973.97 & 437.26 μAmM⁻¹cm⁻². Regarding the anti-interference test, the non-organic glucose sensing response reached the highest level, and the stability remained above 92 % after two weeks.