Surfactant-modified poly(vinyl chloride) membranes as biocompatible interfaces for amperometric enzyme electrodes

Membranes constituted from polymers of differing intrinsic chemical composition as well as poly(vinyl chloride) (PVC) membranes variously modified with plasticising agents were assessed as potential blood contacting interfaces for enzyme electrode use. PVC membranes modified with the nonionic surfactants Tween 80 or Triton X-100 and anionic bis(2-ethylhexyl) hydrogenphosphate exhibited superior biocompatibility over the commercially available porous polycarbonate and Cuprophan haemodialysis membranes. A cationic surfactant (tricaprylylmethylammonium chloride)-modified PVC membrane exhibited the worst biocompatibility. The observed trends in biocompatibility assessed both in terms of sensor response changes and scanning electron surface microscopy were rationalised on the basis of membrane surface topography as well as the modifying effect of additive plasticiser.