Defect-engineered WO3-X pollen-like architectures for highly sensitive and selective detection of Listeria biomarkers

Listeria monocytogenes (LM), a foodborne bacterium capable of causing various diseases, emits 3-hydroxy-2-butanone (3H-2B) and dimethyl trisulfide (DMTS) in its exhaled gas, which can serve as important biomarkers for the bacterium. To date, there have been no reports on the use of dual-selective sensing for these two biomarkers to enhance the accuracy of LM detection. Therefore, we prepared a WO₃ hierarchical architecture using rapeseed pollen templates and employed defect engineering to endow the sensing material with abundant oxygen vacancies for dual-functional monitoring of 3H-2B and DMTS. The results indicate that, thanks to the synergistic effects of abundant oxygen vacancies and unsaturated W⁶⁺ Lewis acids on the surface, the WO 3-X sensor exhibits excellent dual gas sensing performance for 3H-2B and DMTS. Notably, the WO 3-X (N₂) sensor achieves maximum responses of 20.4 and 18.7 for 20 ppm 3H-2B and 20 ppm DMTS at 168 °C and 185 °C, respectively, which are higher than those of other sensors. In addition to high sensitivity, the WO 3-X (N₂) sensors exhibit high selectivity and long-term stability, implying their potential for practical LM detection. Therefore, this work provides a new perspective for the rational design and synthesis of high-performance sensing materials for precise detection of LM to ensure food safety.