The use of zn²⁺-cyclen lumazine as a molecular probe for detection of glutathione (GSH) or glutathione disulfide (GSSG) / Najwa Fatihah Mohd Noor Rawi

The significance of this study is to design a simple and selective molecular probe for detection of glutathione or glutathione disulfide. Zn²⁺-cyclen coordinated lumazine has been chosen to act as the probe in this study. Zn²⁺-cyclen complex which act as the receptor for lumazine will significantly enhanced the fluorescence intensity of lumazine. Glutathione which is a non-fluorescence compound will displace lumazine to coordinate with the Zn²⁺-cyclen complex due to the sulphydril group in its moiety that has higher affinity towards Zn²⁺ as compared to lumazine. The ability of glutathione to coordinate with the Zn²⁺-cyclen complex is indicated by the decrease in the fluorescence intensity of lumazine. There are only two major steps in order to synthesize the probe. The first step is the extraction of cyclen tetrahydrochloride salt into free cyclen. The second step is to do the complexation of free cyclen with Zn²⁺ by using Zn(NO₃)₂.6H₂O. The interaction of lumazine and glutathione with Zn²⁺-cyclen complex was measured by using fluorospectrometer. However, the selectivity of the probe towards glutathione was not determined due to limitations in chemicals available and time constraint.