The Electrochemical Properties Of Polymers Compounds And Their Application In Determination Of Proteins

In order to test the properties of polymers and organic compounds, beside some common methods to determine the molecular weight, shape and so on. Electrochemical method is also needed. So far, the Cyclic Voltammetry is the only method to detect the electrochemical properties of compounds. By the Cyclic Voltammetry the oxidization and reduction peaks can be obtained only to explain the electrochemical properties, and the mechanism and state can not be deduced. So a new method to determine the electrochemical properties is required. In Chapter Two of this thesis, the electrochemiluminesence (ECL) was applied to test the electrochemical properties of polyfluorenes and thiophen and bithiophen organic compounds. ECL is the process whereby species generated at electrodes undergo high-energy electron-transfer reactions to form excited states that emit light. The ion annihilation and coreactant ECL were studied in this assay. The ion annihilation involves the formation of an excited state as a result of an energetic electron transfer between electrochemically generated species, often radical ions, at the surface of an electrode. After the emitter is electrochemically oxidized and reduced, the newly formed radical cation and anion are annihilated to form the excited state species that emits light. In order to generate the radical cation and anion, the scanned potential and pulsed potential were applied. For the coreactant ECL, benzyl peroxide (BPO) is added to the system. The coreactant ECL was generated with scanning from 0 to negative potential. Depending on the polarity of the negative potential, both the polyfluorenes and organic compounds and the BPO were first oxidized or reduced at the electrode to form radicals, and intermediates formed from the coreactant a strong oxidizing species is produced to react with the oxidized or reduced compounds to produce the excited states that release energy to emit light. By this method, the CV and DPV curves can be obtained, and also the curves of ECL and the ECL spectrum. Base on this, the reactant mechanism and the state of the regents during the reactant can be deduced. Besides these, another importance is that the quantum efficiencies of these compounds can be calculated. Especially the polyfluorenes, the highest ECL efficiency reaches 800%, compares to that of the standard compound DPA. From the results that gained, tuning the efficiencies of compounds that consist of certain functional group can be carried out.Protein is one kind of biological molecule, which is very important for life, and it is the physical basis of life. Protein is related with life and its vital processes, and plays very important role in every cell and vital components in living organism. Determination of protein is needed in biochemical studies, biological techniques and the medicine, food and clinical analysis, which attracts the attentions of many scientists to find an easy, quick and high sensitivity way for it. In recent years, resonance light scattering (RLS) technique is successfully applied to determine the protein in serum albumin. Several kinds of RLS probe, such as dyes and surfactants are used. In this thesis, several polymers were used as RLS probe to determine protein in real samples of serum albumins for the first time.In this thesis, three polymers, poly(diallyldimethylammonium chloride) ( PDDA),polymethacrylic acid (PMAA)and polyacrylamide (PAM) were used as RLS probe to analyze the serum albumin samples. In this study, different polymer-protein systems were established for determining proteins. The experiment condition parameters were studied, such as the incubation time, pH value, concentrations of probes and the addition sequence of regents. Meanwhile, the influence of foreign ions, especially some common metal ions was studied. By the established methods, the total protein in synthetic samples containing human serum albumin and bovine serum albumin were analyzed, to make sure the feasibility of this method. After that, it was applied to analyze the total protein in real samples of human serum and bovine serum. The classic Bradford method was also applied to determine the total protein in real samples of serum for contrast. The results were satisfied.