Simulation of Intestinal Gaseous Environment in Order to Verify the Capability of Nanostructured Chemoresistive Sensors to Detect Colorectal Tumor Markers (Benzene, 1-Iodo-Nonane, Decanal)

Studies have proven that neoplasia development and growth are linked to the production and spreading in the body of chemicals, originated from different sources. In the studied case of colorectal cancer (CRC), the main sources of these chemicals (together with the decay of these compounds into smaller products), are: • Products from lipid bilayer peroxidation, generated for instance from contact with free radicals; • Metabolites expelled as discard products from cancerous/benignant cells; • Alteration of the microbiota in the intestine, leading to the variation in concentration of the metabolites produced from these microorganisms; • Vascular endothelial growth factor (VEGF) produced from the tumor itself to stimulate angiogenesis and increase the vascularization in its direct surroundings. Together with some published studies, from the same team, on the other three families of markers, in this work the goal is to study the first group, the peroxidation products, taking as markers the volatile organic compounds (VOCs), already known in literature, 1-iodo-nonane and decanal (highly reactive aldehydes maintaining the hydrophobic tails from the phospholipids), and benzene as sub-product (due to the fact that the main marker itself may turn into other chemicals due to various reactions, some of which are benzene itself and his bis-benzene compounds). These chemicals have been mixed with different concentrations of interferes, commonly produced in the digestive system from various sources (O2, N2, H2, CH4, H2S, NO, NO2, SO2), thus to define which sensors (or sensor arrays) aremost sensitive, and selective, to the presence of the above indicated markers. Nanostructured chemoresistive sensors, widely studied as environmental and industrial real-time monitoring devices, have been used in this work as an opening to a new field of application, the biomedical, with the final goal to provide a new technology to medics and biologists in order to screen the occurrence, and study the degenerative processes, of neoplasms.