Hydrangea-like mesoporous WO₃ nanoflowers with crystalline framework for 3-hydroxy-2-butanone sensing

In this study, a simple and efficient strategy for the construction of hydrangea-like mesoporous WO₃ nanoflowers templated using diblock copolymer PS₁₁₉-PtBA₁₂₉ was developed. The nanoflower shows good gas sensing properties, especially for 3-hydroxy-2-butanone (3H-2B), which is the signature metabolite of Listeria monocytogenes (L. monocytogenes). Therefore, the gas sensing of 3H-2B by hydrangea-like mesoporous WO₃ nanoflowers can be used to detect L. monocytogenes. In the case of 25 ppm 3H-2B as target gas, the response (R_a/R_g) of the hydrangea-like mesoporous WO₃ nanoflowers at 205 °C is 152, where R_a and R_g are the resistances of the sensing device in air and target gas, respectively, and the response and recovery times at 25 ppm are 25 s and 146 s, respectively. Schematic illustration of the formation of hydrangea-like mesoporous WO₃ nanoflowers and its gas sensing implication.