sensing layer coated substrate as above the glucose sensors were placed in a uv box for 10 minutes to crosslink the pvoh removed and stored under vacuum overnight at room temperature the sensors were stored in uncovered petri dishes in a drawer for three and one half months whereupon sensor response wet up and stability were tested as above fig3 illustrates the test results for example 2 testing was performed with the optical instrument described in fig8 the glucose sensors despite the storage conditions showed excellent activity when exposed to varying levels of glucose the response was found to be comparable to the sensors made in example 1 and actually a more rapid rate of oxygen uptake per amount of enzyme used was found in comparison to the sensors made with the acrylamide matrix also the wet up period was found to be nearly instantaneous as dry sensors gave similarly fast kinetics on the first aqueous sample addition to demonstrate the benefits provided by the spacer layer disclosed herein the glucose sensors made as in example 1 were provided with spacer layers as follows a layer of crosslinked pvoh was laid down in stripes from a solution prepared by mixing 250 mg of the crosslinker pvoh solution with 750 mg of a 5 aqueous solution of pvoh average molecular weight of the polymer chains 124 000 to 186 000 the stripes were allowed to dry on the benchtop for a few hours before uv curing and vacuum storage testing was performed with the optical instrument described in fig8 with a preamplifier 174 sensitivity of 100 pa v in this case a single shot protocol was used where a glucose containing blood sample was passed over a hydrated sensor.