Phospholipids in microvolume biofluid samples (≤0.5 μL), including human plasma and single cells, were selectively captured by dispersed magnetic Fe₃O₄@TiO₂ nanocomposite particles (40 μg). A suspension containing Fe₃O₄@TiO₂ nanoparticles was loaded into a glass capillary (i.d. 0.75 mm) by capillary force. The supernatant solution was discarded, while the Fe₃O₄@TiO₂ particles were retained inside the capillary by using an external magnetic field (ca. 1.3 T). The phospholipids on the surface of Fe₃O₄@TiO₂ nanoparticles were directly analyzed using internal extractive electrospray ionization mass spectrometry (iEESI-MS) by pumping ≤1 μL of extraction solution of methanol containing 1.5% ammonia (w/w) through the capillary tube toward the ESI tip. A single sample analysis was accomplished within 4 min. Phospholipids in blood plasma samples from 59 patients with ovarian cancer and 43 healthy controls, and 28 patients with pancreatic cancer and 23 healthy controls were studied. Based on the orthogonal partial least squares discriminant analysis (OPLS-DA), the cancer patients were confidently discriminated from the healthy controls. Phospholipids in single human cells (MV4–11 and NB4) were determined, showing the sensitivity for single cell analysis. Therefore the results demonstrated that rapid cancer differentiation is achieved using this approach through the detection of trace phospholipids in microvolume blood and cell samples with high sensitivity, high specificity, low sample consumption, and high throughput.

中文翻译：

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使用分散固相微萃取结合萃取电喷雾电离质谱法，选择性检测人血浆和单个细胞中的磷脂以区分癌症。

通过分散的磁性Fe ₃ O ₄ @TiO ₂纳米复合颗粒（40μg）选择性捕获微体积生物流体样品（≤0.5μL）中的磷脂，包括人血浆和单细胞。通过毛细管力将包含Fe ₃ O ₄ @TiO ₂纳米颗粒的悬浮液装载到玻璃毛细管（id 0.75 mm）中。丢弃上清液，同时通过使用外部磁场（约1.3 T）将Fe ₃ O ₄ @TiO ₂颗粒保留在毛细管内。Fe ₃ O ₄ @TiO ₂表面的磷脂使用内部萃取电喷雾电离质谱法（iEESI-MS）直接分析纳米颗粒，方法是通过毛细管向ESI尖端泵入≤1μL含1.5％氨（w / w）的甲醇萃取溶液。4分钟内完成一次样品分析。研究了59名卵巢癌患者和43名健康对照者，28名胰腺癌患者和23名健康对照者血浆样品中的磷脂。根据正交偏最小二乘判别分析（OPLS-DA），可以肯定地将癌症患者与健康对照区分开来。测定了单个人细胞（MV4-11和NB4）中的磷脂，显示了对单细胞分析的敏感性。