Chemistry Department, Shiraz University, Shiraz, 71454, Iran.
Chemistry Department, Shiraz University, Shiraz, 71454, Iran.
Anal Chim Acta. 2020 Aug 22;1126:114-123. doi: 10.1016/j.aca.2020.06.006. Epub 2020 Jun 20.
Microfluidic paper-based analytical devices (μPADs) as a potentially powerful analytical platform have recently gained significant attention for on-site monitoring of heavy metal ions, which are one of the most significant environmental concern because of non-degradability and high toxicity. The commonly applied μPADs suffers from some defects, such as heterogeneous deposition of reagent, resulting in poor detection limits and low sensitivity. So, in this work, a three-dimensional origami μPAD combined with PVC Membrane was developed, which can manage problems of movement of colored products or leaching out the dye and leading to color heterogeneity in the detection zones. Furthermore, a waste layer was added to μPAD for loading of more amounts of the analyte, which results in improvement of detection limit. As a proof of concept, the μPAD was used for the analysis of Cu ion. For this purpose, pyrocatechol violet and chrome azurol S as colorimetric reagents were doped into PVC membrane and injected in the detection zone. The proposed μPAD was presented good linearity in the ranges of 5.0-1400.0 and 5.0-200.0 mg L, and the limits of detections of 1.7 and 1.9 mg L in presence of chrome azurol S and pyrocatechol violet, respectively.
微流控纸基分析器件（μPAD）作为一种潜在的强大分析平台，最近在现场监测重金属离子方面引起了广泛关注，因为重金属离子不可降解且毒性高，是最受关注的环境问题之一。常用的 μPAD 存在一些缺陷，例如试剂的不均匀沉积，导致检测限较差和灵敏度较低。因此，在这项工作中，开发了一种与聚氯乙烯（PVC）膜结合的三维折纸 μPAD，它可以解决彩色产物的移动或染料浸出导致检测区颜色不均匀的问题。此外，在 μPAD 中添加了一个废物层，用于加载更多的分析物，从而提高了检测限。作为概念验证，该 μPAD 用于分析 Cu 离子。为此，将邻苯二酚紫和铬天青 S 作为比色试剂掺杂到 PVC 膜中，并注入检测区。所提出的 μPAD 在 5.0-1400.0 和 5.0-200.0 mg/L 的范围内呈现出良好的线性，并且在存在铬天青 S 和邻苯二酚紫的情况下，检测限分别为 1.7 和 1.9 mg/L。
