“…[29][30][31][32][33] Therefore, ZnO could be applicable for chemical gas sensors, SARS-CoV-2 sensing, NO 2 sensing, bio-sensor technologies, solar cells, biomedical nanotechnology, supercapacitors, memory devices, medicine, efficient delivery of curcumin to cancer, spintronic, electrochemical demonstration of vitamin C, optical waveguide sensors, TFTs, OLEDs, photocatalysts, and cancer therapy. [34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51] ZnO has been prepared as various types such as nanorod arrays, [52] quantum dots, [53] seed-like nanostructure, [54] nanosheets, [55] chrysanthemum-like nanostructure, [56] nanotubes, [57] 3D nanowalls, [58] and hexagonal nanostructure. [59] These nanostructural morphologies are extremely important for the performance of the ZnO-based acetone gas sensor.…”