基于SnO_2纳米花气体传感器快速检测牛奶中的单增李斯特菌

以单增李斯特菌特征性代谢物3-羟基-2-丁酮为检测靶点,水热法合成与之匹配的敏感材料,制备出单增李斯特菌特异检测半导体气体传感器。采用X射线衍射和透射电子显微镜手段对材料的结构和形貌进行表征。并分析传感器对3-羟基-2-丁酮标准气体的气敏性能及其在牛奶中单增李斯特菌的检测效果。结果表明,本研究合成的SnO_2材料为纳米花结构。制备出的单增李斯特菌特异检测半导体气体传感器对3-羟基-2-丁酮灵敏度高、响应恢复时间短、选择性和稳定性好。用于检测单增李斯特菌时,传感器的灵敏度与细菌浓度呈现出良好的线性关系,线性方程为lg(S-1)=0.198 3lg C-0.472 5(R~2=0.990 1)。本方法快速灵敏、操作简便,可用于食品中单增李斯特菌的快速检测。

Rapid Detection of Listeria monocytogenes in Milk Base on SnO2 Nanoflower Gas Sensor

The aim of this study was to develop a semiconductor gas sensor for the rapid and sensitive detection of L. monocytogenes by targeting 3-hydroxy-2-butanone, the characteristic metabolite of L. monocytogenes. The sensitive material that matches 3-hydroxy-2-butanone was synthesized by a hydrothermal method and used to fabricate the sensor. The structure and morphology of the material were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The response of the as-prepared sensor to 3-hydroxy-2-butanone calibration gases and its performance for the detection of L. monocytogenes in milk were analyzed. The results indicated that the sensor exhibited high response, quick response-recovery kinetics, and good repeatability to 3-hydroxy-2-butanone. Furthermore, the response showed a good linear relationship with the concentration of L. monocytogenes, and the linear regression equation was lg(S-1)=0.198 3lgC - 0.472 5 (R2 = 0.990 1). This method could be completed within a short time without extensive sample preparation. Accordingly, it has a great potential as a rapid method for the detection of L. monocytogenes in food samples.