The technologies or techniques "e-sensing", in the past decade have had significant developments from the technical and commercial point of view. The term "e-sensing", refers to the ability to reproduce human senses by means of sensors and recognition systems. The proposed work has been developed within the doctoral thesis and is part of a larger research project about sensors underway at the Faculty of Engineering of Messina. The research, combining the knowledge of engineering methods and tools with medical and chemical competence, is oriented to the development of a system able of monitoring the exhaled air for diagnostic purposes, for the realization of electronic systems at a low cost, for the diagnostics in medicine. It was built an artificial olfactory system, known as "electronic nose", which allows monitoring the exhaled air components of patients undergoing a dialysis treatment. This diagnostic non-invasive method is able to provide at low cost, through the specific control of the markers of the exhaled air, some useful information to assess health of dialyzed patients. The realized device, was tested for biomedical applications and mainly for the specific monitoring of volatile biomarkers in the exhaled air, associated with certain medical conditions (eg. NH3 for nephrological diseases). It will allow to obtain an effective early diagnosis of the disease reducing care times and, at the same time, reducing the invasiveness of diagnostic treatments.