Satarpai Thiphol, Siripinyanond Atitaya
Department of Chemistry and Center for Innovation in Chemistry, Faculty of Science, Mahidol University.
Anal Sci. 2018;34(5):605-612. doi: 10.2116/analsci.17P620.
A rapid, easy, and cost effective fabrication method for paper-based analytical devices (PADs) is described. This newly developed method is based on the use of nail polish as an alternative hydrophobic reagent, and the nail polish was resistant to basic and organic solvents. Three approaches for fabrication of paper-based analytical devices (PADs) were investigated, namely writing, stamping, and spraying. The writing approach was carried out by drawing the hydrophobic area of a pre-designed pattern on filter paper with a simple lab-made pen filled with nail polish as the hydrophobic agent. The stamping and spraying approaches required the use of a designed mask, which was made by laser cutting of the magnet rubber sheet. With laser cutting, two types of templates were made, i.e., positive and negative counterparts. The positive counterpart was the inside pattern and the negative counterpart was the outside pattern of the magnet sheets. For the stamping approach, the negative counterpart of the magnet rubber mask was attached onto a simple rubber stamper that was then stamped onto filter paper after loading with nail polish solution. With the spraying method, the positive counterpart was used to cover the hydrophilic area on the paper. Then, the nail polish solution was used with an air brush and sprayed on the paper covered with the magnet rubber mask. All approaches were cost effective and required neither extra equipment nor any pretreatment step. Among all three methods, however, the spraying method was found most suitable for mass production and provided the best resolution when compared with the other two approaches. With this approach, the actual channel widths obtained were similar to the designed widths, with the narrowest possible channel width of 650 μm. Furthermore, a nail polish-treated PAD was prepared by soaking the paper in the nail polish solution. The ability of the nail polish-treated PAD was examined for its resistance to a strong basic solution and an organic solvent (up to 30% ethanol and dichloromethane). The nail polish-treated paper also showed the potential to be used as an organic-aqueous separator.
本文描述了一种用于纸基分析装置（PADs）的快速、简便且经济高效的制造方法。这种新开发的方法基于使用指甲油作为替代疏水剂，且该指甲油对碱性和有机溶剂具有抗性。研究了三种制造纸基分析装置（PADs）的方法，即书写、冲压和喷涂。书写方法是用一支简单的自制笔蘸取指甲油作为疏水剂，在滤纸上绘制预先设计图案的疏水区域。冲压和喷涂方法需要使用通过激光切割磁性橡胶片制成的设计掩膜。通过激光切割制作了两种类型的模板，即正片和负片。正片是磁性片的内部图案，负片是磁性片的外部图案。对于冲压方法，将磁性橡胶掩膜的负片附着到一个简单的橡胶压模上，然后在加载指甲油溶液后将其冲压到滤纸上。对于喷涂方法，使用正片覆盖纸上的亲水区域。然后，使用喷枪将指甲油溶液喷在覆盖有磁性橡胶掩膜的纸上。所有方法都具有成本效益，既不需要额外的设备也不需要任何预处理步骤。然而，在所有三种方法中，发现喷涂方法最适合大规模生产，并且与其他两种方法相比提供了最佳分辨率。采用这种方法，获得的实际通道宽度与设计宽度相似，最窄通道宽度可达650μm。此外，通过将纸浸泡在指甲油溶液中制备了经指甲油处理的PAD。研究了经指甲油处理的PAD对强碱性溶液和有机溶剂（高达30%乙醇和二氯甲烷）的耐受性。经指甲油处理的纸还显示出用作有机-水分离器潜在用途。
