利用毛細管電泳結合線上濃縮技術鑑定麥芽糖分子修飾金奈米粒子

Abstract

本實驗利用毛細管電泳結合反向電極極性樣品堆積法對檸檬酸鈉還原金奈米粒子及麥芽糖修飾金奈米粒子進行偵測。根據兩種金奈米粒子表面修飾分子的不同進行分離，且得到良好的訊號強度。目前鑑定金奈米粒子表面是否有修飾上硫醇分子的方式通常是判定是否有硫金鍵結的形成，例如：UV-Vis吸收光譜儀、X射線光電子能譜分析、核磁共振光譜儀、傅立葉紅外線光譜儀等方式。不過這些方法使用上的受限於靈敏度不佳，當金奈米粒子的濃度過低時，就不容易被偵測到。相對的，毛細管電泳利用金奈米粒子粒徑大小的不同、表面修飾分子在不同酸鹼環境下攜帶電荷的不同及表面修飾分子與界面活性劑 (如十二烷基硫酸鈉) 作用力的不同等方式進行分離。搭配金奈米粒子本身具有表面電漿共振的特性，在520 nm有一強的吸收峰，結合反向電極極性樣品堆積的線上濃縮方式，排除其他干擾物訊號，更可以得到顯著的訊號放大效果，使表面修飾不同分子的金奈米粒子在毛細管電泳中可以清楚的被分辨。因此證明毛細管電泳結合反向電極極性樣品堆積法提供金奈米粒子一種靈敏簡易且清楚有力的鑑定方式。

We employed on-line preconcentration-capillary electrophoresis to characterize maltose-modified gold nanoparticles based on the interaction with sodium dodecylsulfate(SDS). The separation method was demonstrated by the self-prepared maltose-modified gold nanoparticles to differentiate between citrate-modified and maltose-modified gold nanoparticles. The maltose-modified gold nanoparticles are usually characterized the existence of S-Au bond by nuclear magnetic resonance (NMR), electron spectroscopy for chemical analysis (ESCA) or Fourier transform infrared (FT-IR) etc. The limitations of these techniques are low detection sensitivity. The observation of change resulted from S-Au bond is sometimes difficult to detect if low sample concentration is applied. However, the on-line preconcentration-capillary electrophoresis technique applied the high sensitivity to characterize the maltose-modified gold nanoparticles. Several parameters were optimized to get the satisfactory separation efficiency, including the concentration of sodium dodecylsulfate, the pH and concentration of the background electrolyte. Finally, we provided a rapid, simple, high sensitivity method to determine the maltose-modified gold nanoparticles. Furthermore, the developed separation method could apply to characterize other modified gold nanoparticles.