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The non-enzymatic glucose sensing response of pure and Ag-decorated vertically aligned ZnO nanorods grown on Si substrates was investigated. The simple low-temperature hydrothermal method was employed to synthesize the ZnO NRs on the Si substrates, and then Ag decoration was achieved by sputtering. The crystal structure and surface morphologies were characterized by X-ray diffraction, field-emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). The Ag incorporation on the ZnO NR surfaces was confirmed using EDS mapping and spectra. Furthermore, the chemical states, the variation in oxygen vacancies, and the surface modifications of Ag@ZnO were investigated by XPS analysis. Both the glucose/ZnO/Si and glucose/Ag@ZnO/Si device structures were investigated for their non-enzymatic glucose sensing performances with different glucose concentrations. Based on EIS measurements and amperometric analysis, the Ag@ZnO-NR-based glucose sensor device exhibited a better sensing ability with excellent stability over time than pure ZnO NRs. The Ag@ZnO NR glucose sensor device recorded 2792 µA/(mM·cm2) sensitivity with a lowest detection limit of 1.29 µM.

In recent years, the non-volatile resistive random-access memory (ReRAM) has been investigated for next-generation memory devices to fulfill the limitations of commercial transistor-based memory devices. Every now and then, peculiar nanostructures with unique characteristics are reported. However, the influence of distinct nanostructures of a same metal oxide material on the resistive switching performance are not yet surveyed in detail. In this work, two structurally distinct WO3 nanostructures, namely nanoplates and nanocubes, were synthesized through hydrothermal method. The crystalline nature, morphology, atomic composition, and chemical states of WO3 nanostructures were characterized effectively. The fabricated WO3 ReRAM devices were exhibited bipolar resistive switching and the performance of nanoplate and nanocube devices are distinguished in detail.

The need of finding novel functional nanostructured materials to produce cost effective, reliable and high-performance devices are crucial for the future developments. Since the conventional memory technology struggles in various aspects of quantum mechanical and physical limitations, promising next generation memory technology is in high demand. In this study, NiO nanodisks (NDs) and nanorings (NRs) are synthesized by a straightforward hydrothermal route, and the products are characterized using XRD, XPS, SEM, EDS, and TEM. The sandwich structured ReRAM devices have been fabricated by the dispersion of homogenous NDs and NRs on n-Si (100) substrate (bottom electrode) followed by the thermal deposition of Au top electrode on the active layer. Forming free bipolar resistive switching is observed in both fabricated devices; later the device performance has been studied systematically at room temperature and elaborated in detail. Oxygen vacancy produced in the annealed NRs is accounted for the superior switching and conducting filament formation. Finally, we have illustrated the switching mechanism through the construction and annihilation of conductive filaments by oxygen ions and oxygen vacancies present in the crystal lattice along with the band structure alignment of the fabricated device under positive and negative bias followed by the discussion on the fabricated NiO nanostructures. Our proposed NiO nanostructure based ReRAM produced by low-cost one-step hydrothermal method is a promising candidate for the next generation information storage devices.