Bifunctional CuO nanostructured materials preparation for ethanol gas and riboflavin sensing applications

Nanomaterial-based sensors are transforming chemical detection, merging nanotechnology's precision with sensor versatility amid growing chemical health concerns. In our study, we synthesized copper oxide (CuO) nanostructures at various pH levels using a low-temperature hydrothermal process and characterized them in detail. We utilized these CuO nanostructures to develop a chemical sensor for detecting ethanol in gas form and riboflavin in liquid solutions. Remarkably, the sensor utilizing CuO nanostructures synthesized at pH 9 exhibited superior sensing performance for ethanol concentrations ranging from 10 to 100 ppm, with an outstanding response of 132% at 100 ppm ethanol and an operating temperature of 250 °C, and a detection limit at 10 ppm with a response of 36%. For riboflavin detection, the CuO nanostructure-based riboflavin sensor demonstrated high sensitivity (183 µA/µM cm²) within a 50–800 nM concentration range. Our study highlights not only the superior performance, reproducibility, stability, selectivity, and application in real samples of these sensors but also their potential for broader applications by integrating enzymes, antibodies, or other modifications.