Monitoring patient condition via blood diagnostic sensors has major importance for improving healthcare especially for intensive care patients including premature babies. The critical performance parameter of these devices is the wettability of blood over the catalytic / enzyme activator surface with greater blood contact resulting in better sensitivity and reproducibility.

To disperse blood efficiently, conventional sensor design generally uses a coated woven polymer mesh to overlay the active layer however the mesh surface is susceptible to contamination and coating failure leading to errors is readings.

New coating systems have been evaluated by CSMA using plasma pre-treatment followed by coating with a fluoro-carbon terminated poly(butylene oxide-sulphonamide). Imaging SIMS has been used to determine the coating character and coverage in an informative imaging presentation.

SIMS Images of ions F-, (from the coating), O-,,(principally from the oxidised polymer mesh) and C2H- (from the polymer substrate) were mapped. The distribution of O- and C2H- ions confirmed a uniform plasma oxidation process. Ion ratio maps of F-/C2H- eliminated topographic effects and indicated a more uniform coating distribution after plasma oxidation:

Imaging SIMS provides a direct indication of the uptake level and coating uniformity on the different meshes. Plasma oxidation is likely to result in stronger ionic bonding between polymer and coating resulting in greater durability against abrasion.