Department of Applied Chemistry, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan.
Anal Chem. 2020 Apr 7;92(7):4749-4754. doi: 10.1021/acs.analchem.9b05782. Epub 2020 Mar 24.
Distance-based readout is one of the most user-friendly and simple colorimetric signaling methods widely applied for paper-based analytical devices (PADs). This work presents the integration of distance readout PADs into a centrifugal platform enabling affordable, rapid, and sample volume-independent colorimetric assays. Centrifugally assisted distance-based PADs (CD-PADs) eliminate the requirement to use micropipets for sample introduction and reduce the overall time for distance-based assays. All device fabrication steps were performed through computer-controlled print, cut, and laminate (PCL) techniques oriented toward mass production. The inexpensive centrifugal platform was built on a recycled DVD player combined with an open source microcomputer (Arduino). Assay protocols, including rotational velocity and rotation time, were optimized to obtain a maximum dynamic range and reproducible results for sample volume metering (coefficient of variation 3.62%). A colorimetric Ni assay chosen to demonstrate measurements on CD-PADs allowed the detection of nickel ions (Ni) with naked-eye interpretation within 1.5 min and a limit of detection (LOD) of 44.1 ng of Ni, which to the best of our knowledge is the lowest value reported for a distance-based Ni assay.
基于距离的读出是一种最用户友好和简单的比色信号方法，广泛应用于基于纸的分析设备（PAD）。本工作将距离读出 PAD 集成到离心平台中，实现了经济实惠、快速且与样品体积无关的比色分析。离心辅助的基于距离的 PAD（CD-PAD）消除了使用移液管进行样品引入的要求，并减少了基于距离的分析的总时间。所有的器件制造步骤都是通过面向大规模生产的计算机控制打印、切割和层压（PCL）技术完成的。廉价的离心平台是在一个回收的 DVD 播放器上构建的，结合了一个开源的微型计算机（Arduino）。优化了分析协议，包括旋转速度和旋转时间，以获得最大的动态范围和可重复的结果，用于样品体积计量（变异系数为 3.62%）。选择一种比色镍分析来演示 CD-PAD 上的测量，允许在 1.5 分钟内用肉眼解释检测到镍离子（Ni），检测限（LOD）为 44.1 纳克的 Ni，据我们所知，这是基于距离的 Ni 分析报告的最低值。
