Nanometric lamination of zinc oxide nanofilms with gold nanoparticles for self-perceived periodontal disease sensors

Since methyl mercaptan (CH₃SH) concentration from exhaled breath increases marginally by the progress of periodontal disease, the design of a sensing materials that can selectively and accurately discriminate ppb-level CH₃SH among volatile sulfur compounds (VSCs) continue to be strongly demanded for the early diagnosis of periodontitis. Here, the primarily aim is to propose self-perceived-periodontal disease sensors by strategic nanometric lamination of 30 nm-thick ZnO nanofilms with 3 nm-thick Au nanoparticles (NPs) through the two-step process composed of atomic layer deposition and thermal evaporation techniques. Comprehensive microscopic and spectroscopic analysis corroborate the structural and chemical features of ZnO hybridized with Au NPs. The ZnO laminated with Au NPs optimized through size and density control enables to lead the significant enhancement of the gas sensing performance with 4.99% of gas response for 50 ppb of CH₃SH and a detection limit down to 50 ppb. It was highlighted that highly selective detection of ppb-level CH₃SH under a H₂S atmosphere was validated by the Au NP-incorporated ZnO hybrid sensors with reliable and reproducible gas sensing performance.