Reference half-cell and electrochemical sensor with the reference half-cell

A method for manufacturing a reference half-cell, wherein the reference half-cell comprises:

• a housing in which a chamber containing a reference electrolyte is formed, wherein the reference electrolyte is in contact with a medium surrounding the housing via a liquid junction disposed in a wall of the housing wherein
• the liquid junction comprises a diaphragm of porous media,
• the diaphragm having an outer surface defining a volume, the volume including a plurality of pores within the media, each of the plurality of pores having an inner surface,
• the diaphragm further including a coating distributed on the inner surfaces of the plurality of pores and on the outer surface, such that the coating at least partially covers the inner surfaces and the outer surface, wherein the coating includes at least one metal, the method comprising the steps of:
• providing a porous diaphragm in a housing wall of a housing;
• forming a chamber for accommodating a reference electrolyte in the housing of the reference half-cell;
• and
• coating the diaphragm with a coating comprising at least one metal,
• wherein the step of coating comprises contacting the diaphragm with a solution containing the at least one metal in the form of a metal salt or in the form of nano particles and depositing from the solution the coating within the pores and on the surface of the diaphragm.