Abstract: 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.

Key words: Listeria monocytogenes, 3-hydroxy-2-butanone, hydrothermal method, gas-sensing performance, nanoflower, response