Before revision: History An example is the pH-sensitive LAPS that uses LEDs in combination with (semi-conducting) silicon and pH-sensitive Ta2O5 ([SiO2| SiO<sub>2| ];[Si3N4| Si<sub>3N<sub>4| ]) insulator.
After revision: History An example is the pH-sensitive LAPS that uses LEDs in combination with (semi-conducting) silicon and pH-sensitive Ta2O5 ([SiO2| SiO2 ];[Si3N4| Si3N4 ]) insulator.