a hydrophobic, porous, oxygen permeable layer positioned between said reagent layer and said support, such that oxygen can permeate to {TAIL ~ said layer} containing oxidase from {HEAD ~ both surfaces} of said layer containing oxidase 
a hydrophobic , porous , oxygen permeable layer positioned between said reagent layer and said support , such that oxygen can permeate to { TAIL ~ said layer } containing oxidase from { HEAD ~ both surfaces } of said layer containing oxidase
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH