Systems and methods are provided for a deep sea pH sensor. In one embodiment, a method for manufacturing a pH sensor comprises forming a sensor electrode in a working surface of a die wherein the sensor electrode is able to sense the pH of a liquid and forming at least one isolation groove around the sensor electrode on the working surface of the die, wherein the die has a wide street around the sensor electrode and the at least one isolation groove. The method further comprises mounting the die onto a base and securing a seal on the working surface in the wide street, wherein the seal surrounds the isolation groove, the seal sealing the liquid within the portion of the working surface of the die containing the sensor electrode and the isolation groove, when the pH sensor is subjected to high pressure.