Simulation and design of an ISFET-based biosensor for estimating Ca2+ concentration in sweat

The development of highly-sensitive technologies for biological analytes detection has provided a positive contribution in the clinical practice, especially in precision diagnostics and biomedical research. Biosensors prove to be ideal in bioanalytical applications, as they provide several advantages, not only economically, but also in terms of time, precision, and miniaturization. In our work, the design of an ion-sensitive field effect transistor (ISFET), able to detect the presence of calcium ions in sweat is presented. The clinical case of interest is the chronic renal failure's disease, in which variations in the electrolyte balance may occur, involving changes in the concentration of Ca2+ in sweat. The device is designed considering two domains: the semiconductor domain and the electrolyte domain. The obtained results are promising towards the development of an easy-to-use and non-invasive device, that could be useful for the early diagnosis and the constant monitoring of such a pathology.