| Electrochemiluminescence (ECL) analysis is an analytical method based on thecombination of chemiluminescence (CL) and electrochemisty (EC). ECL has manyadvantages, such as high sensitivity, high selectivity, low background signal, widelinear response range, and is a highly integrated technology that combines theadvantages of multiple techniques. ECL generally includes annihilation ECL andcoreactant ECL. Compared with annihilation ECL, coreactant ECL system has theadvantage that ECL emission can be generated by applying a potential in only onedirection, hence coreactant ECL can usually use more simple instruments and haswider applications. Therefore, looking for new ECL coreactants is of greatsignificance for both fundermental ECL study and analytical applications of ECL.The aim of this thesis is searching for new coreactants of Ru(bpy)32+, studyingnew ECL mechanisms, and applying new coreactant-Ru(bpy)32+ECL systems in theanalytical chemistry field. The thesis consists of the following four chapters:In chapter one, the general introduction of ECL, types of ECL and relative ECLmechanisms, and advances in ECL studies and applications were described.Especially, the ECL mechanism and application of Ru(bpy)32+coreatant ECL systemswere introduced in detail.In chapter two, Sn2+ion was studied as the coreatant of Ru(bpy)32+ECL system.The ECL behaviors of Ru(bpy)32+-Sn2+system were investigated and related ECLmechanism was studied and discussed. It was revealed that Sn2+could serve as a goodcoreatant of Ru(bpy)32+with serveal obvious advantages, such as high sensitivity, lowtoxicity, wide linear response range and low cost.In chapter three, we found that the addition of mercury ion (Hg2+) couldsignificantly inhibit the ECL intensity of Ru(bpy)32+/Sn2+coreactant system. Hg2+could be detected by a new electrochemiluminescence sensor based on its specificreaction with a strongly electrochemiluminescent (ECL) Ru(bpy)32+/Sn2+coreactantsystem. It was revealed that this inhibition effect resulted from the competitivereactions between Ru(bpy)33+-Sn2+and Hg2+-Sn2+. Based on the inhibition ofRu(bpy)32+/Sn2+ECL by Hg2+, a simple, label-free, sensitive and selective sensor for aqueous Hg2+has been constructed. Under the optimum experimental conditions, thelinear range and detection limit of Ru(bpy)32+/Sn2+ECL system for Hg2+were5.0×10-5~1.0×10-7mol/L and1.0×10-8mol/L, respectively.In chapter four, according to the precipitation reaction between Sn2+and S2-, andstrong ECL reactions between Sn2+and Ru(bpy)32+, a method for S2-detection wasestablished. The optimum conditions for the ECL inhibition have been investigated indetails. Under the optimum conditions, a simple, sensitive method for the detection ofS2-has been developed. Experimental results showed that the method could detectboth high (5.0×10-4~1.0×10-2mol/L) and low (1.0×10-4~1.0×10-7mol/L)concentrations of S2-. The detection limit of S2-by this method was5.0×10-8mol/L. |
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