Novel Synthesis and Applications of Gold Nanoclusters : (1) Sensing of GSH, (2) Sensing of Mercury(II), and (3) Cluster-Assisted LDI MS

• Main Authors: Tzu-Heng Chen, 程祖衡
• Other Authors: Wei-Lung Tseng
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/09615533478891669699

碩士 === 國立中山大學 === 化學系研究所 === 100 === This paper, contain three parts, focus on develop synthesis method for novel functional nanocluster, base on its special optical and reactive property. In the first part, lysozyme VI was mixed with HAuCl4 under acidic condition(pH~3) and yield blue fluorescent Au8 nanocluster. When this Au8 cluster was incubate under alkaline condition (pH~12) a size evolution from Au8 to Au25 took place and monitored with fluorescence spectrum, MALDI MS, DLS. On the other hand, on the role of structural characteristic, fluorescence of Au8 cluster can be quenched by GSH as GSH induced core-etching reaction took place. Take advantage of this reaction, GSH in RBC can be quantitatively analysis by Au8 cluster. Compare with standard medical analysis method, this assay got comparable quantitative result and advantage in environmental friendly, low cost and low sample demand. Follow the first part, it was knowing that Hg2+quench fluorescence of Au25 but Au8 cluster. The second part of research development a ratiometric fluorescence assay for Hg2+ in drinking water sample, by control size evolution of nanocluster mentioned in first part by adding Ag+ into protein direct synthesis nanocluter process. Under optimize condition of bimetallic nanocluster synthesis, two separately fluorescence peak locate under 613 nm and 471 nm represent bigger size and smaller nanoclusters. Using fluorescence intensity ratio of two wavelength, concentration of Hg2+ in water sample can be determined by standard addition method with high reproducibility. Limit of detection was determined to be 0.1 and 0.4 nM, both lower than EPA permitted level in drinking water. On the third part, SA and HAuCl4 was mixed under water contained acetonitrile solution and SA caped nanocluster was form. This nanocluster after self essemble possess special crystalline and surface phenomenon and fit matrix for high reproducible laser desorption/ionization mass spectrometry. Compare with traditional matrix SA, the cluster matrix show 6.6% in RSD with 33%. And the desorption/ionization efficiency of nanocluster matrix is also much higher. Insulin, myoglobin and HSA sample can be quantitative with this matrix with mean RSD lower than 10%.