Detection of Volatile Organic Compounds by Using a Nanoporous Zeolite Layer.

The selective detection of volatile organic compounds (VOCs) represents a recently investigated approach that could provide information about the alteration of biological processes. As reported in literature, human biological samples (e.g., saliva, urine, breath, etc.) express different VOCs that could provide information on human health status (e.g., drugs therapies, metabolic/biochemical processes, lung cancer, oral squamous cell carcinoma, hepatocarcinoma etc.). In this work we focused on the detection of butanoic, propanoic, and butanedioic acids since they are contained in different biochemical processes. The aim of this work is the fabrication of thin nanoporous films of synthetic zeolite for the selective adsorption/desorption of butyric, propionic, and succinic acids. The detection is performed by the assessment of emission profiles through a photoionization technique. Results evidenced that zeolite layer is highly selective to propionic acid, allowing a higher adsorption. Conversely, butyric acid emissive profile evidenced adsorption levels 5 times less respect to the propionic acid.