Ha. Brooks et al., EFFECT OF SURFACE-ATTACHED HEPARIN ON THE RESPONSE OF POTASSIUM-SELECTIVE ELECTRODES, Analytical chemistry, 68(8), 1996, pp. 1439-1443
Heparin (or hydrolyzed heparin) was covalently attached on the surface
of derivatized cellulose triacetate membranes, which were subsequentl
y impregnated with the potassium-selective ionophore valinomycin. The
resulting ion-selective electrodes presented near-Nernstian response t
o potassium and had selectivity coefficients of the same order of magn
itude as those of conventional poly(vinyl chloride)-based electrodes.
It was found that the heparin layer does not alter significantly the r
esponse characteristics of the electrodes. The biological activity of
the immobilized heparin (or hydrolyzed heparin) was measured in terms
of its inactivation of blood coagulation factor Xa. It was found that
the covalently anchored hydrolyzed heparin was not biologically active
, but the immobilized heparin was able to inactivate factor Xa. Theref
ore, by covalently attaching heparin on the surface of ion-selective e
lectrodes, electrodes with improved blood compatibility characteristic
s may be prepared.