Development of novel high-sensitivity chemiluminescence assay for luminol using thiourea derivatives

We have screened about 100 thiourea derivatives in order to develop a sensitive chemiluminescence detection for luminol derivatives. Among these derivatives, we found a new compound, 2-(3-methylthioureido) thiazole, that could be used to measure luminol in the presence of hydrogen peroxide (H(2)O(2)). The detection limits of luminol and N-(4-aminobutyl)-N-ethylisoluminol (ABEI) were 10 fmol and 100 fmol, respectively. The mechanism of proposed chemiluminescence reaction was studied by electron spin resonance (ESR) with and without superoxide dismutase (SOD) and the addition of ethanol. The results showed that 2-(3-methylthioureido) thiazole has the ability to generate hydroxyl radical from H(2)O(2), and produces intense chemiluminescence in the presence of luminol. The proposed novel chemiluminescence reaction for luminol and luminol derivatives was applied to a high performance liquid chromatography (HPLC) assay for amino compounds.