The present invention provides a polymer membrane enhanced with cured
epoxy resin for use as the outer membrane of biosensors. The membrane
includes approximately 30-80% epoxy resin adhesives, 10-60% polymer such
as poly(vinyl chloride), polycarbonate and polyurethane and 0-30%
plasticizers and 5-15% surface modifier reagent such as polyethylene
oxide-containing block copolymers. Utilizing the polymer membrane of the
present invention, a three-layered sensing element has been developed.
This sensing element will be particularly useful for miniaturized
biosensors used for in vitro blood measurements or for continuous in vivo
monitoring such as implantable biosensors. This element includes an
enzyme layer, an interference-eliminating layer and the novel polymer
member of the present invention as the outer polymer layer. This novel
sensing element shows excellent response characteristics in solutions and
has an extremely long lifetime. This technology is particularly useful
for improving the lifetime of implantable biosensors.