The invention relates to a method of preserving a sensor in a container, said sensor comprising a sensing area of metallic or a semi-conducting material covered with molecules having a MW>100 Dalton, said molecules being bound to the material wherein at least the sensing area of the layer is kept submerged in a storage solution, said storage solution having a composition that consists for at least 80% by volume of at least one compound chosen from water, ethanol, triethylene glycol and isopropanol, with the provisios that if the concentration of ethanol is at least 80 vol. % of the storage solution ethanol is present in a concentration of no more than 93% by volume of the storage solution; if water is present, it is present in a concentration of less than 80% by volume of the storage solution. The invention also relates to a container containing a sensor and a storage solution.