Verification of ISFET response time for millisecond range ion stimulus using electronic technique

The ion sensitive field effect transistor (ISFET) is a popular sensor in biomedical electronics and has been used to date mainly for relatively low speed applications, such as measurement of pH of common biomedical fluids. However, there is a growing interest in sensing rapidly changing ion activity for applications including chemical synapse and rapid DNA sequencing. In this reported work, it is demonstrated that the response time of the ISFET is sufficient for these applications. The results obtained are used to determine the factors that affect high speed chemical sensing with the ISFET.