The sensor 4, wherein the species sensing electrode portion is doped with {HEAD ~ a material} selected from {TAIL ~ the group} consisting of Ce, Pb, Ag, Mn, Mo, W, Ca, Li, Na, K, Cs, Zr, Ge, Sb, Mg, Sr, Sc, Ti, Nb, Fe, Co, Ni, Cu, Rh, Pd, Ga, In, and Sn, and mixtures and combinations thereof 
The sensor 4 , wherein the species sensing electrode portion is doped with { HEAD ~ a material } selected from { TAIL ~ the group } consisting of Ce , Pb , Ag , Mn , Mo , W , Ca , Li , Na , K , Cs , Zr , Ge , Sb , Mg , Sr , Sc , Ti , Nb , Fe , Co , Ni , Cu , Rh , Pd , Ga , In , and Sn , and mixtures and combinations thereof
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH