Chemiluminescent determination of lucigenin using thioureid derivatives Original Research Article

Various thioureid derivatives were studied as new reagents for detecting trace amounts of lucigenin by chemiluminescence (CL). A new compound containing a heterocyclic substituent group, α-(3-methylthioureido)-ε-caprolactam (MTCL) showed strong ability to generate CL from lucigenin. The CL mechanism of lucigenin with MTCL also was investigated by ESR spectrometry using spin trapping methods, and its CL spectrum. The mechanism was speculated as follows; that O2− generated by the reaction of MTCL and O2 in alkaline solution react with lucigenin, and light is emitted. Under optimum condition, the detection limit of lucigenin was 12 fmol (signal-to-noise ratio = 3), and the measurable range was from 1.2 × 10−15 to 1.2 × 10−8 moles per assay. The proposed CL assay of lucigenin was applied to dehydroepiandrosterone sulfate after ion pair solvent extraction (detection limit 5 pmol).