Reference electrodes that include a solid electron conductor; an interlayer; and a polymeric membrane layer comprising a polymer composition, the polymer composition comprising at least one silicone-containing polymer and at least one ionic liquid, wherein the polymeric membrane layer and the polymer composition are essentially plasticizer free and the silicone-containing polymer and the ionic liquid are miscible as determined using a thermodynamic method that shows a single glass transition temperature (Tg) of a composition including the at least one silicone-containing polymer and the at least one ionic liquid, wherein the interlayer is disposed between the solid electron conductor and the polymeric membrane layer. Also disclosed are electrochemical measurement systems including such reference electrodes.