Novel CCD-based pH imaging sensor

We propose and demonstrate a novel pH imaging sensor based on the Charge Coupled Device (CCD) technology. This device consists of pH sensing parts, which sense pH value and transform a pH value to electric charges, and conventional CCD parts, which transfer the electric charges to read out circuit. A thin Si/sub 3/N/sub 4/ film which acts as the hydrogen ion-sensitive membrane was used in the pH sensing film. The prototype devices were fabricated and was confirmed the device operation using pH equivalent voltages. It was found that the output signal from the imaging sensor was lineally changed from pH 0 to 14 and successfully observed a pH image on a black and white TV monitor.