The Preparation, Characterization And Its Analytical Application Of Aqueous Fluorescence Gold Nanoparticles

Charter One: The preparation methods, spectroscopy characterization and analytical application of aqueous gold nanoparticles are reviewed there. Charter Two: The novel ffluorescence gold nanoparticles (AuNPs) were synthesized using citrate reduction of HAuCl₄ in aqueous solution with hydrothermal method. The prepared AuNPs were characterized by transmission electron microscopy (TEM), UV-Vis and fluorescence spectroscopy. It was observed that the AuNPs were monodispersed with mean diameter of 15.0 nm exhibited the stable ffluorescence emission band at 367 nm, under the excitation at wavelength of 264 nm. When we change the concentration of AuNPs, the fluorescence emission band did not change, still at 367 nm. The enhancements of fluorescence intensity are proportional to the concentration of gold nanoparticles, indicating the bare gold nanoparticles exhibit the efficient fluorescence. Charter Three: A novel method has been developed for determination of micro amounts of 6-mercaptopurine (6-MP), a sulfur analogue of adenine, employing a ffluorescence gold nanoparticles (AuNPs). The fluorescence enhancement was significantly observed upon the AuNPs self-assembled with 6-MP. The fluorimetric determination indicated that 6-MP could be quantified with good linear range of 6.35×10-8～3.05×10-7 mol/ L, with a low detection limit of 4.81×10-10 mol/ L, under optimal conditions. The relative standard deviation (n=11) is 1.76% at 1.27×10-7 mol/ L 6-MP concentration level. The proposed method has been successfully applied to determination of the drug in spiked human urine. The results were satisfactory, which indicates that the method is not only sensitive, simply, but also reliable and suitable for practical application. Charter Four: It is the report on the determination of proteins with gold nanoparticles (AuNPs) by fluorescence spectroscopy. The results show that, at pH 7.43 of phosphate buffer, the fluorescence intensity of AuNPs can be enhanced by proteins, including BSA, HSA and γ-IgG; but the fluorescence emission band at 367nm, under the excitation at wavelength of 264nm; after adding the proteins into Au colloids. Based on this, a novel quantitative assay of proteins has been proposed. Under optimal conditions, the linear ranges of the calibration in the curves were 5.73×10-13～5.73×10-8 mg/ml, 3.84×10-13～3.84×10-8 mg/ml, and 6.40×10-13～6.40×10-8 mg/ml for BSA, HSA, and γ-IgG, respectively. The detection limits were 4.83×10-15 mg/ml, 2.71×10-15 mg/ml, 3.20×10-15 mg/ml for BSA, HSA, and γ-IgG, respectively. The method has been applied to the analysis of total proteins in human serum samples collected from the hospital, and compared to CCB method.