The Investigation And Analytical Application Of The Metal Ions Complexes Compound In Luminol Electrochemiluminescence System

Two parts are included in this thesis. In the first part of this thesis, the basic principle, the new progress and the advantages in Electrochemiluminescent (ECL) assay etc., are reviewed. In addition to these, the ECL reaction mechanisms of some useful ECL systems, the main problems and the future prospect on the ECL analysis were also given in this part. In the second part of this thesis, we mainly concentrated on the study of the highly sensitive luminol ECL methods for some metal ions based on their complexes compound form.Electrochemiluminescence method is one of the most interesting subjects in analytical chemistry field. This technique not only retains the advantage of the conventional chemiluminescence (CL) analysis, but also offers some advantages over more conventional CL. Firstly, the ECL reaction can be easily regulated and manipulated by the applied potential. Firstly, the ECL reaction can be easily regulated and manipulated by the applied potential. Secondly, the ECL emission is concentrated close to the vicinity of the electrode, which can be shaped and accurately positioned in relation to the optical measurement system for maximum sensitivity. Thirdly, the analyte can be in-situ modified electrochemically to form the corresponding CL active specie without the chemical contamination due to the addition of the necessary reactants in the corresponding CL reactions. Thus, ECL analysis, compared to CL analysis, offered the more alternative potentials to regulate the ECL reaction for analytical purpose.Since the luminol-based ECL phenomena was firstly observed by Harvey in 1929, the ECL was paid much attention by the analysts, and a lots of analytes had been detected with ECL analytical technique during the 1980s and 1990s. This approach has many obvious advantages over other analytical methods, and it has been applied successfully to many fields, such as life science, clinical medicine, environment, immunoassays and DNA probe analysis etc. Nowadays, analysts are working on biological chip and exploiting ECL substance etc.Our research works are divided into two parts. Firstly, although the enhancing effect of Pb(II), Cd(II) and Fe(III) for the weak ECL signal of electro-oxidation Luminol were observed, they are weak. However, we further found that, when these ion become their ions complexes compounds, such as, Fe(o-Phen)33+, Cd-T-I-H2QS and Pb-7-I-H2QS, they could greatly enhance the weak ECL signal arising from the electro-oxidated or electro-reducing Luminol in alkaline medium. Based on these observations and the optimum experimental conditions developed, the relative ECL intensity was linear with increasing Fe(III) concentration in the range 4.0+10-7 to 4.0+10-6 mol/L and a 1.8+10-7 mol/L detection limit for Fe(III) could be achieved; The linear range of Cd(II) was from l.0+10-7 to 1.0+10-4 g/mL and with 3.6+10-8 g/mL detecting limit; The linear range of Pb(II) was from 2.0+10-7 to 1.0+10-4g/mL and with a detecting limit of 6.2+10-8 g/mL.In addition to these, a novel sampling device with the nL in volume was designed. Then, based on the combination of this device with an ECL-based micro-detector, we successfully determinate H2O2 by ECL-based microfluidic system. Our results further prove that the ECL detector owned the great potential in this research field.