探討1-Thio-β-D-glucose表面修飾螢光金奈米團簇於腦瘤細胞、大腸桿菌與線蟲代謝後之螢光變化

Abstract

螢光金奈米團簇（Gold Nanoclusters, Au NCs）具有獨特的光學性質、易於進行表面修飾及良好的生物相容性等優點，使其具有生物顯影及生物感測之應用性。本研究利用穀胱甘肽做為還原劑製備出發橘紅色螢光之金奈米團簇，並以β-D硫代葡萄糖（1-Thio-β-D-glucose）修飾其表面，合成出表面修飾葡萄糖之螢光金奈米團簇（TGlu-Au NCs）。我們利用顯微注射及餵食的方式，使TGlu-Au NCs進入秀麗隱桿線蟲（C. elegans）體內，在線蟲的咽、體腔及肛門都能清楚看到TGlu-Au NCs的螢光成像。使用大腸桿菌（E. coli）觀察TGlu-Au NCs的螢光變化，得到大腸桿菌濃度上升會使TGlu-Au NCs螢光強度下降之結果，顯示TGlu-Au NCs做為生物感測器之潛力。另將腦瘤細胞之糖酵解酶取出與TGlu-Au NCs反應，發現TGlu-Au NCs的螢光強度隨著反應時間愈長而下降愈多，顯示腫瘤細胞發生糖解作用，證實TGlu-Au NCs可利用腦瘤細胞的瓦氏效應行標記之作用。

Fluorescent gold nanoclusters have been widely employed in the bioimaging and biosensing because of their unique optical properties, facile surface modification and high biocompatibility. In this study, we used L-Glutathione as a reductant to prepared fluorescent gold nanoclusters (Au NCs) and then the surface of Au NCs was modified with 1-Thio-β-D-glucose (TGlu-Au NCs). TGlu-Au NCs were respectively microinjected and fed into C. elegans to investigate their in vivo fluorescence imaging. The fluorescence of TGlu-Au NCs was easily visible in the lumen of the digestive system, extending from the pharynx to the anal region. Furthermore, the fluorescence changes of TGlu-Au NCs were studied with E. coli. TGlu-Au NCs at 0.4 (O.D.) showed higher decreasing rate of fluorescence intensity than that of TGlu-Au NCs at 0.27 (O.D.). In addition, the glycolytic enzyme of brain tumor cells (U-87 MG) was added into TGlu-Au NCs solution. After the reaction with the glycolytic enzyme, the fluorescence intensity of TGlu-Au NCs was decreased with the increase of time. The results confirmed the Warburg effect of TGlu-Au NCs in brain tumor cell.