Single-Layered Paper-Based Microfluidic Devices Made by Paint-Spraying Technique with Great Barrier Resistance for Colorimetric Assays

The single-layered paint-spraying paper based microfluidic devices (sp-μPADs) have been for the first time integrated with the colorimetric assay. The polymethyl methacrylate (PMMA) board was applied as the mask instead of the iron mask, reducing the power requirement of the cutting machine. The paint was sprayed into the paper, which blocked the pores of the paper and constructed the hydrophobic barrier on the paper. The paint barrier was highly resistant to the various kind of chemicals and the minimum channel dimensions was 1.4 mm. By using the PMMA masks with different designs, the sp-μPADs with different designs have been fabricated and successfully applied to the single analyte assay of iron or bovine serum albumin (BSA) and the simultaneous assay of copper and nickel. Moreover, the feasibility of the multiplexed assay of eight analytes was also demonstrated. The analytical performances indicated that the fabricated sp-μPADs offered a promising platform in the colorimetric assays of either single or multiple analytes.

本研究首次将单层喷涂纸基微流控器件（sp-μPADs）与比色测定法相结合。研究采用聚甲基丙烯酸甲酯（PMMA）板替代铁质掩模作为模具，降低了切割机的功率需求。将涂料喷涂至纸张中，涂料可封堵纸张孔隙并在纸张上构筑疏水屏障。该涂料屏障对多种化学物质具有优异的耐受性，最小通道尺寸可达1.4 mm。通过使用不同设计的PMMA掩模，可制备出多种构型的sp-μPADs，并成功应用于铁或牛血清白蛋白（BSA）的单分析物测定，以及铜与镍的同时测定。此外，本研究还验证了8种分析物多重测定的可行性。分析性能测试结果表明，所制备的sp-μPADs为单分析物或多分析物的比色测定提供了极具应用前景的平台。