Transistor-Based Impedimetric Monitoring of Single Cells

Abstract

As the interest in personalized medicine in general and individualized therapies in particular is increasing steadily, there is a great need for biomedical sensing platforms that offer the highest possible sensitivity, reliability, stability, versatility, and accuracy as well as the lowest limit of detection. While not all biosensors offer the same possibilities, ion sensitive field-effect transistors (ISFET) are a well-understood and well-established platform that can be applied for many needs in the field of biomedicine. With the possibilities to modify and functionalize the device surface for cell cultures and parallel measurements with many sensing points on one device, ISFET arrays offer an optimized platform for chemical sensing (pH, ion concentration, etc.) and for the sensing of biological species like cells, DNA, and proteins. In this chapter, we present impedance sensing with ISFETs as a universal tool for cellular recordings down to single cell level and give an overview of recent measurements with this versatile approach. In accordance with the classical ECIS method we termed our technique Field-Effect Transistor Cell-substrate Impedance Sensing (FETCIS). In this chapter the fundamental technique as well as the electronic model to explain the recorded FETCIS spectra is elaborated showing several applications, which are not accessible with ECIS so far.