本計畫利用溶膠凝膠法於順磁性奈米微粒表面包覆不同矽氧烷基聚合物，如四甲基矽氧
烷(tetramethoxysilane；TMOS )、四乙基矽氧烷(tetraethoxysilane；TEOS )、3-氨基丙基三甲
基矽氧烷(3-aminopropyltriethoxysilane；APTES)，探討這些不同修飾的矽磁微粒對DNA 的
吸附特性，其中以四甲基矽氧烷修飾矽磁微粒吸附DNA 的能力最好；在pH 2.8 - pH 7.8 溶
液中，矽磁微粒吸附DNA 的能力隨酸鹼值下降而提高。所製備之矽磁微粒已成功於真實樣
品，如菌液中，吸附DNA 並進行特定基因之檢測。 The extraction and isolation of DNA from biological samples is one of the most commonly used
procedures in genetics, molecular biology. The quality of isolated nucleic acids is critical in
obtaining accurate and meaningful analytical data.
The extraction of DNA from crude biological matrixes is commonly performed by solid-phase
extraction (SPE), which has largely replaced liquid-liquid extraction for purifying DNA. The most
widely used solid supports for SPE of DNA have been silica-based particles. Silica particles
modified to create a cationic surface have also been shown to bind plasmid DNA electrostatically,
and thus could be used as a solid-phase matrix for DNA purification. Though numerous methods
that prepare magnetite/silica nanocomposites for adsorbing DNA have been developed for purifying
DNA, the search for the best purification procedure and comparison of different materials in terms
of the extraction efficiency of DNA has gained less attention. Our research was focused on testing
different magnetite/silica nanocomposites based on covalent or noncovalent modification of the
silica surface with 3-aminopropyltriethoxysilane (APTES) in search of the best efficiency, fewer
processing steps, and shorter analysis times for DNA extraction.
