In paper-based microfluidics, the simplest devices are colorimetric, giving qualitative results. However, getting quantitative data can be quite a bit more difficult. Distance-based devices provide a user-friendly means of obtaining quantitative data without the need for any additional equipment, simply by using an included ruler or calibrated markings. This article details the development of a quantitative DNA detection device that utilizes the aggregation of polystyrene microspheres to affect the distance that microspheres wick through filter paper. The microspheres are conjugated to single-stranded DNA (ssDNA) oligomers that are partially complementary to a target strand and, in the presence of the target strand, form a three-strand complex, resulting in the formation of aggregates. The higher the concentration of the target strand, the larger the aggregate, and the shorter the distance wicked by the microspheres. This behavior was investigated across a wide range of target concentrations and under different incubation times to understand aggregate formation. The device was then used to successfully detect a target strand spiked in extracted plant DNA.

中文翻译：

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纸基微流控设备中基于距离和微球聚集的DNA检测。

在基于纸张的微流控技术中，最简单的设备是比色法，给出定性结果。但是，获取定量数据可能要困难得多。基于距离的设备只需使用随附的标尺或已校准的标记，即可提供无需任何其他设备即可获得定量数据的用户友好方式。本文详细介绍了定量DNA检测装置的开发，该装置利用聚苯乙烯微球的聚集来影响微球通过滤纸芯吸的距离。将微球缀合至与目标链部分互补的单链DNA（ssDNA）低聚物，并在存在目标链的情况下形成三链复合物，从而形成聚集体。目标链的浓度越高，聚集体越大，微球芯吸的距离越短。在广泛的目标浓度范围和不同的孵育时间下研究了这种行为，以了解聚集体的形成。然后将该设备用于成功检测掺入提取的植物DNA中的靶链。