Electronic nose based on hybrid free-standing nanofibrous mats for meat spoilage monitoring

Food safety and quality control have become nowadays a major priority for the sake of public health to protect consumers from the risks of foodborne diseases and food poisoning. For instance, in the case of the decomposition of meat protein, ammonia and biogenic amines content can be used as a parameter to evaluate meat quality. However, practical analytical methods for in loco evaluation of amines release by meat are still on demand. Herein, we report hybrid free-standing composite nanofibers as sensing platforms to identify volatile amines (ammonia, methylamine and trimethylamine), as one of the main components of the gas produced in the process of meat spoilage, and to monitor fish freshness at room temperature. For that purpose, SiO2:In2O3, SiO2: ZnO and SiO2 nanofibers, prepared by electrospinning followed by thermal treatment, were deposited onto interdigitated electrodes and then modified with polyaniline and poly(styrene sulfonate). Seven sensing units of distinct compositions were employed in an impedimetric electronic nose, and multidimensional projection was used to help in the discrimination of standard analytes as well as of analytes released during the deterioration of fish real samples. The frequency selection resulted in improved discrimination by multidimensional projection and the sensor array showed an excellent performance to be applied in fish spoilage monitoring.