Shandong Analysis and Test Center, Qilu University of Technology (Shandong Academy of Sciences), Jinan, China.
Department of General Surgery, The First Affiliated Hospital of Shandong First Medical University, Jinan, China.
PLoS One. 2024 Sep 6;19(9):e0308424. doi: 10.1371/journal.pone.0308424. eCollection 2024.
Hardness is one of the basic parameters of water, and a high-level hardness of drinking water may be harmful to human health. Thus, it is very important to monitor drinking water hardness. In this work, a portable lateral flow distance-based paper sensor for the semi-quantitative detection of drinking water hardness is demonstrated. In the presence of Ca2+/Mg2+, the hydrogel can be formed via the chelation between sodium alginate and Ca2+/Mg2+, inducing a phase separation process. The viscosity change of the sodium alginate solution is directly related to the Ca2+/Mg2+ concentration and can be determined by the water lateral flow distance on test strips. The sensor successfully realizes the quantification of Ca2+ and Mg2+ in the range of 0-10 mmol L-1 and 4-20 mmol L-1, respectively. The recoveries are found varied from 95% to 108.9%. The water hardness is acceptable for drinking if the Cr values lies in the range of 0.259 to 0.419, and it is high with the Cr value above 0.595. Remarkably, the performance of the sensor is comparable with the commercial kit for real water samples, which avoids the subjective judgment. Overall, this method provides a portable approach for semi-quantitative detection of drinking water hardness with the merits of convenience and low cost, which shows great potential for the potential application.
水的硬度是水的基本参数之一，饮用水的高硬度可能对人体健康有害。因此，监测饮用水硬度非常重要。在这项工作中，展示了一种用于半定量检测饮用水硬度的基于侧向流动距离的便携式纸传感器。在 Ca2+/Mg2+存在的情况下，水凝胶可以通过海藻酸钠与 Ca2+/Mg2+之间的螯合作用形成，从而引发相分离过程。海藻酸钠溶液的粘度变化与 Ca2+/Mg2+浓度直接相关，可以通过测试条上的水侧向流动距离来确定。该传感器成功地实现了对 Ca2+和 Mg2+在 0-10 mmol L-1 和 4-20 mmol L-1 范围内的定量检测。回收率在 95%至 108.9%之间变化。Cr 值在 0.259 至 0.419 范围内时，水的硬度可接受饮用，而 Cr 值高于 0.595 时则较高。值得注意的是，该传感器的性能与商用试剂盒相当，可以避免主观判断。总的来说，该方法提供了一种用于半定量检测饮用水硬度的便携式方法，具有方便和低成本的优点，在潜在应用中显示出巨大的潜力。
