Liang Kai, Wu Hongmei, Li Yan
Laboratory of Interdisciplinary Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101 China.
GuangDong Bio-healtech Advanced Co., Ltd, Foshan City, 52800 GuangDong Province China.
Clin Proteomics. 2017 Jan 19;14:5. doi: 10.1186/s12014-017-9139-z. eCollection 2017.
Detection of low-abundance biomarkers using mass spectrometry (MS) is often hampered by non-target molecules in biological fluids. In addition, current procedures for sample preparation increase sample consumption and limit analysis throughput. Here, a simple strategy is proposed to construct an antibody-modified target plate for high-sensitivity MS detection of target markers such as insulin, in biological fluids.
The target plate was first modified with gold nanoparticle, and then functionalized with corresponding antibody through chemical conjugation. Clinical specimens were incubated onto these antibody-functionalized target plates, and then subjected to matrix assisted laser desorption ionization mass spectrometry analysis.
Insulin in samples was enriched specifically on this functional plate. The detection just required low-volume samples (lower than 5 µL) and simplified handling process (within 40 min). This method exhibited high sensitivity (limit of detection in standard samples, 0.8 nM) and good linear correlation of MS intensity with insulin concentration (R = 0.994). More importantly, insulin present in real biological fluids such as human serum and cell lysate could be detected directly by using this functional target plate without additional sample preparations.
Our method is easy to manipulate, cost-effective, and with a potential to be applied in the field of clinical biomarker detection.
使用质谱（MS）检测低丰度生物标志物通常受到生物体液中非靶分子的阻碍。此外，当前的样品制备程序会增加样品消耗并限制分析通量。在此，提出了一种简单的策略，用于构建抗体修饰的靶板，以对生物体液中的胰岛素等靶标标志物进行高灵敏度MS检测。
首先用金纳米颗粒修饰靶板，然后通过化学偶联用相应抗体进行功能化。将临床标本孵育在这些抗体功能化的靶板上，然后进行基质辅助激光解吸电离质谱分析。
样品中的胰岛素在该功能板上被特异性富集。检测仅需要少量样品（低于5 μL）且简化了处理过程（在40分钟内）。该方法具有高灵敏度（标准样品中的检测限为0.8 nM）以及MS强度与胰岛素浓度之间良好的线性相关性（R = 0.994）。更重要的是，使用该功能靶板无需额外的样品制备即可直接检测真实生物体液（如人血清和细胞裂解液）中存在的胰岛素。
我们的方法易于操作、成本效益高，并且有潜力应用于临床生物标志物检测领域。
