English  |  正體中文  |  简体中文  |  全文筆數/總筆數 : 49287/83828 (59%)
造訪人次 : 7149639      線上人數 : 51
RC Version 7.0 © Powered By DSPACE, MIT. Enhanced by NTU Library & TKU Library IR team.
搜尋範圍 查詢小技巧:
  • 您可在西文檢索詞彙前後加上"雙引號",以獲取較精準的檢索結果
  • 若欲以作者姓名搜尋,建議至進階搜尋限定作者欄位,可獲得較完整資料
  • 進階搜尋
    請使用永久網址來引用或連結此文件: http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/24857


    題名: A cooperative effect of bifunctionalized nanoparticles on recognition: Sensing alkali ions by crown and carboxylate moieties in aqueous media
    作者: Lin, S. Y.;Chen, C. H.;Lin, M. C.;徐秀福;Hsu, Hsiu-fu
    貢獻者: 淡江大學化學學系
    日期: 2005-06-22
    上傳時間: 2009-12-01
    出版者: American Chemical Society (ACS)
    摘要: Reported here is a cooperative effect that the sensing efficiency of the active group on gold nanoparticles (GNPs) can be significantly influenced by another proximal functional group. We previously developed a visual sensing scheme for K+ by 15-crown-5-CH2O(CH2)12SH functionalized GNPs in aqueous matrix. Upon adding K+, the GNP solution changes from red to blue. Such a transform is triggered by a 2-to-1 sandwich complexation of crown to K+, resulting in the red shift of surface plasmon absorption due to GNP aggregation. Herein, we discover that introducing a second functionality, thioctic acid (TA), onto GNPs significantly affects the sensing efficiency of crown moieties (15-crown-5-CH2O(CH2)nSH and 12-crown-4-CH2O(CH2)nSH, where n = 4, 8, and 12). The rate constant of K+ recognition by TA- and 15-crown-5-CH2O(CH2)4S-bifunctionalized GNPs is more than 4 orders of magnitude faster than the others containing longer methylene chains. The same chain-length dependence is also found in the case of Na+ sensing by 12-crown-4 functionalized GNPs. The discrepancy in sensing performance is attributed to a cooperative effect that the negatively charged carboxylate of TA may preorganize the crown moiety for K+ recognition. This method is applied to measure K+ and Na+ in human urine by UV−visible spectrometry. By adjusting the concentrations of GNPs, the dynamic ranges tuned for K+ and Na+ are, respectively, 6.25 μM−1.12 mM and 0.156−4.00 mM, suitable for real samples pretreated simply by 10-fold dilution. The results ([K+] = 20.3 mM, [Na+] = 45.1 mM) agree with those obtained from ICP-AES ([K+] = 19.8 mM, [Na+] = 43.8 mM).
    關聯: Analytical Chemistry 77(15), pp.4821-4828
    DOI: 10.1021/ac050443r
    顯示於類別:[化學學系暨研究所] 期刊論文

    文件中的檔案:

    檔案 描述 大小格式瀏覽次數
    0KbUnknown221檢視/開啟
    index.html0KbHTML56檢視/開啟

    在機構典藏中所有的資料項目都受到原著作權保護.

    TAIR相關文章

    DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library & TKU Library IR teams. Copyright ©   - 回饋