MOF-templated synthesis of cobalt-doped zinc oxide superparticles for detection of the 3-hydroxy-2-butanone microbial biomarker

It is important to detect the foodborne pathogens, such as Listeria monocytogenes (LMs), in food and water since the bacteria often induced serious illnesses in the global world. The bacteria generate the microbial volatile organic compound (VOC), 3-hydroxy-2-butanone (3H-2B), which could be used as a biomarker to indirectly detect the microbial contamination. Herein, ordered cobalt-doped zinc oxide superparticles (Co₃O₄/ZnO SPs) have been constructed by using MOFs as templates and have been employed as a sensing material to develop gas sensors for highly sensitive and selective detection of LMs. The 1% Co₃O₄/ZnO SPs based gas sensor showed a fast response, highest sensitivity and selectivity towards the 3 H-2B when compared to other dosage of Co doping. The proposed gas sensing mechanism is discussed. By using the Co₃O₄/ZnO SPs based sensors, a rapid bacteria detection platform was developed, with a high sensitivity and selectivity to trace the LMs at low concentrations. The gas sensing performance of the Co₃O₄/ZnO SPs based sensors has great potential applications for fast and sensitive detection of microbial contaminations. The study also introduces a way to construct MOF derived superstructure nanomaterials for gas sensing and other applications.