Study On The Application Of Polyoxometalates Nanoparticles In Medicament And Protein Analysis

Polyoxometalates (POM) have a lot of unique properties as a kind of special metallic oxides. Because of these properties, they played an important role in a variety of field, such as catalysis, anticancer drugs and analytical reagents, all of these have attracted much attention by researchers. With the development of nanotechnology, the synthesis and application of POM has come into nanometer field. At present, many kinds of POM nanoparticles have already been reported, including nanoball, nanorod, nanowire, nanotube and the nanohollow on the film. And all these POM nanoparticles prepared by using a lot of different ways, such as template-assisted, electrochemical processes, vapor-liquid-solids-assisted and liquid-assisted. As a sort of analytical reagent, the POM could be used to determine the metal ion, some medicament and protein molecule. But most of these have been determined by using POM molecule not the POM nanoparticles. In this paper, two kinds of POM nanoparticles have been prepared and applied to analyse medicament and protein by UV and light scattering signals. The main content is as follows:1. A spectrophotometric method for the determination of dopamine is described based on a type of ployoxometalates-dye complex nanoparticles which are composed by crystal violet with molybdate-iodine tetrachloride. By the reaction between dopamine and molybdate-iodine tetrachloride reagent in acidic medium, the color of the solution has changed, and an analysis method of dopamine could be constructed. By spectrophotometric signal, a linear relationship has been obtained when the concentration of dopamine is in the range of 5.0×10^-71.4×l0^-5 mol·L^-1, and the detection limit is 9.0×l0^-8 mol·L^-1 (3σ). This method has been used for analysis of the injection containing dopamine hydrochloride.2. A controllable synthetic route of the Ag₃PW₁₂O₄₀ nanocubes was investigated on our work, and these prepared nanocubes were used as an analysis probe to detect the protein and medicament.(1). It was found in this contribution that Keggin-type of polyoxometalates nanocubes could be formed in aqueous medium under the adjustment of dimethylformamide (DMF), which could be changed from solid nanocubes to hollow ones with the increasing of temperature. Further investigations showed that this Keggin-type of polyoxometalates nanocubes can specifically interact with prion protein, and the light scattering signals were enhanced in proportional to the content of prion in the range of 3.36-840 ng·mL^-1.(2). The interaction of Ag₃PW₁₂O₄₀ nanocubes and lysozyme was studied with light scattering (LS) spectral. Ag₃PW₁₂O₄₀ nanocubes can be linked with lysozyme, and strongly enhanced their LS intensity. In the PB buffer solution with pH value of 6.8, the enhancing LS intensity was in proportion to the concentration of lysozyme in a range of 0.5-140μg·mL^-1. The effects of reaction time, pH of solution, coexisted ions and organic regents were studied in this work. Under optimum conditions, the detection limit of lysozyme (3σ) is 0.04μg·mL^-1 with nanoparticles as a probe. This method was successfully used to the detection of trace lysozyme.(3). A light scattering (LS) method for the determination of dopamine is described based on Ag₃PW₁₂O₄₀ nanocubes. The dopamine can interact with Ag₃PW₁₂O₄₀ nanocubes, and their LS signal was strongly enhanced. In the CH₃COOH-CH₃COONa buffer solution with pH value of 5.0, we can determine dopamine in a range of 3.0×10^-8-1.2×l0^-5 mol·L^-1, and the limit of determination (3σ) is 1.4×10^-8 mol·L^-1. The recommended method has been used for analysis of the injection containing dopamine hydrochloride.