IBM Research Europe-Zurich, Säumerstrasse 4, CH-8803 Rüschlikon, Zurich, Switzerland.
Institute of Biological Interfaces (IBG1), Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.
Angew Chem Int Ed Engl. 2021 Nov 2;60(45):24064-24069. doi: 10.1002/anie.202110974. Epub 2021 Oct 5.
Forming hydrogels with precise geometries is challenging and mostly done using photopolymerization, which involves toxic chemicals, rinsing steps, solvents, and bulky optical equipment. Here, we introduce a new method for in situ formation of hydrogels with a well-defined geometry in a sealed microfluidic chip by interfacial polymerization. The geometry of the hydrogel is programmed by microfluidic design using capillary pinning structures and bringing into contact solutions containing hydrogel precursors from vicinal channels. The characteristics of the hydrogel (mesh size, molecular weight cut-off) can be readily adjusted. This method is compatible with capillary-driven microfluidics, fast, uses small volumes of reagents and samples, and does not require specific laboratory equipment. Our approach creates opportunities for filtration, hydrogel functionalization, and hydrogel-based assays, as exemplified by a rapid, compact competitive immunoassay that does not require a rinsing step.
采用光聚合技术来制备具有精确几何形状的水凝胶具有一定的挑战性，因为该技术涉及到有毒化学物质、冲洗步骤、溶剂和庞大的光学设备。在这里，我们引入了一种新的方法，即在密封的微流控芯片中通过界面聚合原位形成具有明确定义几何形状的水凝胶。水凝胶的形状是通过使用毛细管钉扎结构的微流控设计和使含有水凝胶前体的溶液从相邻通道接触来编程的。水凝胶的特性（网格尺寸、分子量截止值）可以很容易地进行调整。该方法与基于毛细作用的微流控技术兼容，速度快，使用的试剂和样品体积小，且不需要特定的实验室设备。我们的方法为过滤、水凝胶功能化和基于水凝胶的分析提供了机会，例如快速、紧凑的竞争性免疫分析，该分析不需要冲洗步骤。
