A calcium-selective optrode based on the fluorescence of dansylated troponin

Troponin C (TnC) is covalently labeled with a fluorescent probe molecule dansylaziridine and immobilized on polyethyleneimine-impregnated cellulose. An optrode is constructed by attaching the treated cellulose membrane to the distal end of a bifurcated fiber-optic cable. Because fluorescence is enhanced as Ca+2 binds with the immobilized dansylated troponin (TnCDANZ), this system can be used as a calcium sensor for monitoring plasma Ca+2 levels.