State Key Laboratory of Analytical Chemistry for Life Science and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University , Nanjing 210023, People's Republic of China.
Anal Chem. 2017 Feb 7;89(3):2131-2137. doi: 10.1021/acs.analchem.6b04891. Epub 2017 Jan 11.
Though microfluidic paper analytical devices (μPADs) have attracted paramounting attentions in recent years as promising devices for low cost point-of-care tests, their real applications for blood analysis are still challenged by integrating sample preparation with different detection modes on a same μPAD. Herein, we developed a novel μPAD, which well coupled automatic serum extraction with reliable dual mode iron health tests: fluorescent analysis for Fe and colorimetric ELISA for ferritin. All these functions are made available by in situ carbon dots (CDs) and AuNPs sequential patterning techniques. For CDs immobilization, hydrothermal reaction was taken on paper, to which a patterned through-hole polydimethylsiloxane (PDMS) mask was applied. None fluorescence CDs (nF-CDs) were generated on exposed regions, while the fluorescent CDs (F-CDs) were generated simultaneously on covered regions. Sensitive serum iron quantification was realized on the F-CDs modified regions, where Fe ion can selectively quench the fluorescence of F-CDs. For AuNPs immobilization, electroless plating was taken on nF-CDs modified regions. The resulting AuNPs on nF-CDs layer on one hand triggered the coagulation of blood cells and thus led to the longest ever wicking distance for serum separation, on the other hand facilitated colorimetric enzyme linked immunosorbent assay (ELISA) for detection of serum ferritin. Combining the two readings, the μPAD can provide reliable measurement for serum iron and serum ferritin in whole blood. Furthermore, as CDs and AuNPs modified μPAD has the features of easy handling, low-cost, lightweight, and disposability, it is accounting for a promising prototype for whole blood point-of-care analysis.
尽管微流控纸分析器件（μPAD）作为用于低成本即时护理测试的有前途的设备近年来引起了极大的关注，但它们在血液分析中的实际应用仍然受到挑战，因为需要在同一μPAD 上将样品制备与不同的检测模式集成在一起。在此，我们开发了一种新型的 μPAD，它很好地将自动血清提取与可靠的双模式铁健康测试相结合：用于 Fe 的荧光分析和用于铁蛋白的比色 ELISA。所有这些功能都是通过原位碳点（CDs）和 AuNPs 顺序图案化技术实现的。对于 CDs 的固定化，在纸上进行水热反应，并在其上施加图案化的贯穿孔聚二甲基硅氧烷（PDMS）掩模。在暴露区域生成无荧光 CDs（nF-CDs），而在覆盖区域同时生成荧光 CDs（F-CDs）。在 F-CDs 修饰区域实现了敏感的血清铁定量，其中 Fe 离子可以选择性猝灭 F-CDs 的荧光。对于 AuNPs 的固定化，在 nF-CDs 修饰区域进行无电电镀。一方面，所得的 nF-CDs 层上的 AuNPs 触发血细胞的凝聚，从而导致血清分离的最长虹吸距离，另一方面有利于血清铁蛋白的比色酶联免疫吸附测定（ELISA）检测。结合两种读数，μPAD 可以为全血中的血清铁和血清铁蛋白提供可靠的测量。此外，由于 CDs 和 AuNPs 修饰的 μPAD 具有易于操作、低成本、重量轻和可一次性使用的特点，因此它是用于全血即时护理分析的有前途的原型。
