| 摘要: | 近年來奈米材料應用於生醫檢測的領域中有蓬勃的發展，其中以各種複合材料製得具有高螢光強度及穩定性質的奈米粒子，亦不斷被證實有極佳的效能與臨床應用價值。這些掺入螢光物質的奈米微粒，螢光強度遠高於傳統有機螢光分子，又有多種可選擇材料與方法使粒子表面具適當官能基與生化分子產生共價鍵結，使其有優異條件作為蛋白質或核酸標記物（1, 2）。
我們的研究參考 Tan et. al.（3）所發表文獻，以溶膠凝膠法配合微乳化方式製備以TEOS（tetraethoxysilane）為起始物之奈米矽凝膠微粒，所製得為粒徑約65nm、大小均一之奈米粒子。我們同時亦製備以 TMOS （tetramethoxysilane）為起始物之奈米粒子，以比較兩種材質粒子在水溶液中的分散性、tris(2,2’-bipyridyl)ruthenium(II)
（Ru(bpy)32+）吸附進入粒子速率的差異。此外亦探討溶液性質，如酸鹼值、溶液組成對奈米矽凝膠微粒吸附濃縮Ru(bpy) 3
2+ 特性之影響。
免疫分析實驗以未掺入染劑的奈米矽凝膠微粒作為抗體標記，免疫反應於聚苯乙烯微粒上進行，反應完成後方加入固定量Ru(bpy) 32+，待Ru(bpy) 32+ 吸附濃縮於奈米標記內，再分離微粒與溶液，將兩部分分別注入光學分析系統，進行Ru(bpy) 3
2+ 螢光訊號偵測；當分析物濃度越高時，則所測得之螢光訊號越小。以奈米矽凝膠微粒作為”
先驅標記物”的優點為其性質穩定、可長期保存、對各種抗體或抗原之標記方法簡易、且反應具普遍適用性；預期建立另一種經濟、簡易且靈敏的免疫分析模式。
In this work, we have made an effort to establish a new immunoassay method that
utilizes silica nanoparticles as an universal pre-probe. The nanometer-sized silica particles
were synthesized by a two-step procedure using the reverse-micelle and sol-gel technique.
With the characteristics of silica nanoparticles for adsorbing and concentrating cations,
none-doped silica nanoparticles were conjugated with antibodies first, after immunoreaction,
signal molecules, such as fluorescence luminephores, could be added and concentrated into
silica nanoparticles. Then the residual concentration of luminephores was determinated
based on fluorescence intensity. Using this pre-probe conjugation strategy, other cationic
luminiphores, fluorophores, electrochemical active compounds, etc., can also be used in
analogous methods. Because silica gel is a polar, biocompatible material, the nonspecific
binding, denaturization, inactivation of biomolecules can be diminished. The properties of
long-term stability and easy surface bioconjugation of silica nanoparticles make this
universal pre-probe can play an important, versatile role in immunoassays. |
