Effect of glutathione on peroxyoxalate chemiluminescence of hypericin as the fluorophore.

Herein, the effect of amino acid Glutathione (GSH) on Peroxyoxalate Chemiluminescence was studied for the first time. Hypericin (HYP) was employed as the efficient fluorophore. The investigated parameters included rise and fall rate constant for the chemiluminescence burst, theoretical and experimental maximum intensity, the time-needed to reach maximum intensity and the total light yield emission which theoretically was evaluated using the pooled intermediate model by a computerized non-linear least-squares curve fitting program (KINFIT). Furthermore, based on observed quenching effect of GSH, the Stern-Volmer plot in quencher concentration range of 2.8×10(-6) to 3.4×10(-5)M with KQ value of 1.59×10(4) was calculated. The bimolecular quenching rate constant (Kq) was also estimated about 2.8×10(12) and M(-1) S(-1). Moreover the system was applied successfully to determine glutathione in biological samples.