Amperometric enzyme electrode for Ca2

Abstract An amperometric enzyme electrode for the detection of Ca 2+ using NADP + -dependent isocitrate dehydrogenase coupled to an N -methylphenazinium tetracyanoquinodimethanide (NMPTCNQ) electrode is described. The electrode responds to Ca 2+ in a linear manner and is unaffected by the presence of Na + (165 mM) and K + (5 mM).