Specific Identification of Listeria monocytogenes in Food Using a QCM Sensor Based on Amino-Modified Mesoporous SiO2 with Enhanced Surface-Active Capabilities

<i>Listeria monocytogenes</i> (<i>LM</i>) poses a serious threat to food safety and public health. Current detection methods suffer from drawbacks such as expensive equipment, complex procedures, and time-consuming processes, highlighting the urgent need for a simple, rapid, accurate, and cost-effective detection approach. The bacterial metabolite 3-hydroxy-2-butanone (3H2B), due to its high abundance, can serve as a reliable biomarker for detection. Herein, ordered mesoporous silica nanoparticles (MSNs) were synthesized via a one-pot method and subsequently functionalized with APTES. The NH₂-MSNs-2 exhibits extremely high sensitivity (768 Hz@50 ppm) and selectivity towards 3H2B due to its high specific surface area, abundant mesoporous structure, and weak chemical adsorption between amino groups and the 3H2B. The quartz crystal microbalance (QCM) sensor developed based on this material demonstrated outstanding performance in testing the contamination levels of <i>LM</i> in food. This study provides a solid foundation for further exploring the fundamental mechanisms of QCM sensors in the real-time, non-invasive detection of <i>LM</i>, while also demonstrating significant application potential in the field of food safety assurance.