Study On The Enhancement Of Tris(2,2'-bipyridyl)ruthenium(ii) Electrochemiluminescence And Applications In Capillary Electrophoresis

Electrochemiluminescence (ECL) is the combination of electrochemistry and chemiluminescence. During all ECL systems, Ru(bpy)₃²⁺, with high luminescent efficiency and good solubility in both aqueous and nonaqueous solvents, is considered to be the most efficient and widely used ECL reagent. In recent years, more and more ECL studies have focused on the improvement of the sensitivity and stability and the expanding of its application range, followed by a growing number of reports. Nanomaterials including metal nanoparticles (NPs) and carbon nanotubes (CNTs), which are widely used in analytical areas, are widely used to enhance ECL intensity and thus improve detection sensitivity. Another method which was widely adopted is the solid phase ECL. All these methods can obviously improve the sensitivity of ECL detection.Ru(bpy)₃²⁺-ECL is an ultrasensitive analytical method, and thus it is considered to be an ideal technology to couple with capillary electrophoresis (CE), and the CE-ECL technology has gradually become a potential new kind of separation and analysis technique.The main work of this thesis is summarized as follows:1. A simple, novel, fast and sensitive method for the determination of tris(2,3-dibromopropyl) isocyanurate (TBC) by ECL technology coupled with silver nitrate (AgNO3) enhancement in acetonitrile at gold nanoparticles(AuNPs)- electrodeposited gold electrode was proposed. In the presence of gold nanoparticles and small amounts of AgNO3, the ECL intensity was obviously enhanced. The mechanism of the ECL enhancement of the system is studied in detail.2. Based on Ru(bpy)₃²⁺ solid phase ECL, Ru(bpy)₃²⁺ was directly modified at the glassy carbon electrode (GCE) surface by electrodeposition, without using additional host materials. With the addition of small amounts of potassium nitrate, the ECL intensity was obviously enhanced. Because there were no host matrics involved, the approach facilitated electron transfer and avoided the problems such as lacking of permeability, conductivity and uniformity of the solid matrics. The modified GCE showed stable ECL with N,N-dimethyl ethanolamine as the co-reactant. The modified GCE was used to the determination of amino acids and had excellent selectivities to some amino acids, and finally the method was adopted to determine sibutramine hydrochloride in human urine.3. The Pt electrode with the electrodeposition of gold nanostructures was prepared and applied in enhanced ECL detection for CE. Difenidol hydrochloride was used as a model analyte. Compared with using bare electrode, the detection sensitivity was significantly improved by ca. 2 orders of magnitude. Notably, the nanogold was prepared at the surface of electrode and no nanogold was added to the electrophoretic buffer or detection cell, thus causing no interference to the separation. With high sensitivity and good reproducibility, this method provides a promising platform for the determination of pharmaceuticals which have a tertiary amine group such as difenidol.