Study On The Applications Of Gold Nanoparticles In Capillary Electro-phoresis And Spectroscopic Analysis

Owing to the special properties and effects, gold nanoparticles were extensively applied to the analytical chemistry researches. Based on the properties of gold nanoparticles, their ap-plications in analytical chemistry were studied. Gold nanoparticles were coated on the inner surface of silica capillaries to separate proteins. A new colorimetric method based on the gold nanoparticles was established to detect melamine and Hg2+ respectively.This thesis consists of four sections summarized as follows:Chapter 1:ReviewA brief review of gold nanoparticles in terms of properties and preparation and their ap-plication in chemical analysis methods were given, on which the research contents of this the-sis were proposed.Chapter 2:Separation of Proteins by Gold Nanoparticles Modified Capillary Electro-phoresisGold nanoparticles were coated on the inner surface of fused silica capillaries by physi-cal adsorbtion, and the electroosmotic flow and efficiency of separation for two similar pro-teins were investigated. Results demonstrated the coated capillaries were good enough to de-crease the electroosmotic flow and the adsorption of the proteins on the capillary wall and improve the separation efficiency. Under the optimized conditions, HSA and BSA were sepa-rated at the base line and the linearity was established over the concentration versus peak area with correlation coefficients of 0.9848 and 0.9943, and the detection limits (S/N=3) of 0.83 and 0.80μg/mL for HSA and BSA, respectively.Chapter 3:Detection of Melamine with Gold Nanoparticles as Spectral Probe by Laser Thermal Lens SpectrometryA simple and rapid laser thermal lens spectrometry method for detection of melamine using gold nanoparticles as probe was proposed. It was found that the color of melamine solu-tion changed evidently in the presence of gold nanoparticles, which provided a platform for laser thermal lens spectrometry detection of melamine in milk productions. It was showed that this method presented higher detection sensitivity and the intensity was proportional to the concentration of melamine ranging from 0.12-1.0μmol/L with the limit of detection of 5.8 ng/mL. The proposed method was used to detect melamine in milk production with recovery of 96.0～102.6% and RSD of 2.6～3.2%.Chapter 4:Detection of Mercury(Ⅱ) with Cysteine functionalized Gold Nanoparticles as Spectral Probe by Laser Thermal Lens SpectrometryDetection of Hg2+ by colorimetric method on the basis of cysteine functionalized gold nanoparticles was studied. With amino on the surface, the nanoparticles were easily coordi-nated with Hg2+ in the aqueous solution, led to the aggregation and colorimetric response. Thus, the purpose of Hg2+ detection was achieved. Results showed that the proposed method exhibited preferable sensitivity and was linear in a certain concentration range and with the detection limit of 0.0349μg/mL. The contents of Hg2+ in water samples were successfully detected with recovery over the range from 97.6 to 99.0% and RSD from 0.71 to 2.6%.