Research progress of semiconductor metal oxides-based gas sensors towards metabolic gas of Listeria monocytogenes: A mini review

Acetoin (also known as 3-hydroxy-2-butanone) is a metabolic biomarker gas of Listeria monocytogenes (food pathogenic bacteria). Sensitive and selective detection of acetoin biomarker can lead to indirect online monitoring of Listeria monocytogenes, which has attracted much attention in gas sensing field recent years. At present, different from the mature researches towards other VOCs biomarkers, the researches on acetoin gas sensors are newly emerged and still in the infancy. The structure of sensing materials needs to be optimized and the intrinsic sensing mechanism still needs to be further clarified. In order to promote the development of acetoin gas sensors, in this mini-review we present recent advances of acetoin gas sensors based on semiconductor metal oxides (SMOs) for the first time, expound the sensing mechanism, and put forward the research shortcomings and future prospects.