A gas sensor for measuring a gas content in an electrolyte, including: a first channel and a second channel separated by a septum; and a tip, the first channel and the second channel are closed by the tip; a first electrode is located in the first channel, extends to an outer surface of the tip, and exposed on the outer surface of the tip; a second electrode is located in the second channel, extends to the outer surface of the tip, exposed on the outer surface of the tip, and spaced apart from the first electrode; an electrolyte in contact with the outer surface of the tip, in contact with the first electrode and the second electrode, and exposed to an outer surface of the gas sensor; a voltage source; and a current meter, wherein the electrolyte is not present in the first channel and the second channel.