Potential-Resolved Electrochemiluminescence Of Fluorescein In Aqueous Solution And Luminol, Lucigenin In Organic Solvents And Enhancement And Inhibition Of Luminol Chemiluminescence By Some Organic Compounds

The recent developments in the fields of electrochemiluminescence (ECL), potential-resolved electrochemiluminescence (PRECL) and chemiluminescence (CL) enhancement and inhibition were reviewed. It was pointed out that the previous PRECL studies are limited to the classical ECL system in aqueous solutions, and the PRECL of fluorescent compounds with high quantum efficiency and the PRECL of the classical ECL system in organic solvents still remain unknown. In addition, the mechanisms of the CL enhancement and inhibition are not fully understood. This dissertation studied the PRECL of fluorescein in aqueous solution, the PRECL of luminol and lucigenin in organic solvents, and the CL and ECL enhancement and inhibition of luminol by some organic compounds. The main results are as follows:1. The PRECL behavior of fluorescein at a polycrystalline gold electrode was studied. Five ECL peaks were observed at 0.94 (ECL-1), 1.51 (ECL-2), 1.34 (ECL-3), -0.06 (ECL-4), -0.73～-1.11 V (vs SCE) (ECL-5, a broad weak wave), respectively, on the curve of ECL intensity versus potential. The effect of potential scan direction and range, the presence of N₂ and O₂, electrolyte, the concentration of NaOH, KBr and fluorescein on fluorescein ECL was examined. The ECL of eosin Y (tetrabromofluorescein) was also conducted. The UV-visible absorption spectra and fluorescence spectra of fluorescein during the reaction were studied. The spectra of various ECL peaks at different potentials were analyzed. The mechanisms for fluorescein ECL at a polycrystalline gold electrode have been proposed. All the ECL peaks except ECL-3 was due to that the electro-oxidation product of fluorescein or...