Stability of ISFET and its new measurement protocol

The aim of this report is to provide a new protocol for evaluating pH sensitivity films and stability of pH-ISFET. A light testing technique to evaluate stability of the pH sensing film was developed by using on–off lighting in a box. The long-term stability was strongly influenced by exposures to a fluorescent light and the drifts of ISFET were accelerated under the light with an intensity of more than 1000 lux. A good correlation for ISFET baseline drift was observed between conventional long term tests and this light testing technique.