Multimodal Sensor for Simultaneous Proton and Light Sensing Using a Hole and Electron Accumulation Technique

A novel multimodal biosensor based on complementary metal-oxide-semiconductor technology is presented. In the sensor, electrons and holes are simultaneously handled as signal electrical charges. We call this technique the hole and electron accumulation technique (HEAT). The HEAT sensor maps two phenomena (i.e., ion concentration and light power) perfectly at the same time using the same pixel. This paper describes the sensing mechanism and basic characteristics of the HEAT sensor. In addition, we successfully demonstrate a multimodal sensor for the simultaneous sensing of pH (power of hydrogen or proton concentration) and light power.