Smartphone-based turbidity reader.
Smartphone-based turbidity reader.
复制标题
基于智能手机的浊度读取器。
DOI：
10.1038/s41598-019-56474-z
复制
发表时间：
2019
影响因子：
4.6
通讯作者：
Ozcan,Aydogan
中科院分区：
文献类型：
--
作者：
CeylanKoydemir,Hatice;Rajpal,Simran;Gumustekin,Esin;Karinca,Doruk;Liang,Kyle;Göröcs,Zoltan;Tseng,Derek;Ozcan,Aydogan
由于细菌、污染物和其他有害颗粒，水质正在显着恶化，损害水生生物并降低饮用水质量。因此，能够使用浊度计等以经济有效的方式快速准确地测量水质非常重要。浊度计通常使用不同的照明角度来测量光通过样品的散射和透射率，并将这些读数转换为基于标准比浊浊度单位 (NTU) 的测量结果。传统浊度计具有高灵敏度和特异性，但它们不便于现场携带，并且需要电力才能在现场操作。在这里，我们展示了一款基于智能手机的现场便携式且具有成本效益的浊度计。该移动浊度计包含一个与智能手机后置摄像头耦合的光机械附件，其中包含两个用于照亮水样的白色发光二极管、将从样品收集的光传输到摄像头的光纤、用于形成图像的外部镜头以及用于均匀照明样品的扩散器。包括智能手机在内，这款经济高效的设备重量仅为约 350 克。在我们的移动浊度计设计中，我们结合了两种照明方法：透射法，其中光纤直接放置在样品比色皿下方，与光源成 180° 角；浊度法，其中光纤放置在样品比色皿侧面，与光源成 90° 角。使用智能手机捕获这些光纤电缆端面的图像，并使用定制的书面图像处理算法进行处理，以自动量化每个样品的浊度。使用透射率和浊度读数，我们的移动浊度计在 0.3 NTU 到 2000 NTU 的大动态范围内实现了精确测量。我们基于智能手机的浊度计的准确性能也得到了在洛杉矶（美国）收集的各种水样、细菌加标水样以及柴油污染水样的证实。这款经济高效的基于智能手机的浊度计的检测限约为 0.3 NTU，可以成为在资源有限的环境中筛选水质的有用分析工具。
Water quality is undergoing significant deterioration due to bacteria, pollutants and other harmful particles, damaging aquatic life and lowering the quality of drinking water. It is, therefore, important to be able to rapidly and accurately measure water quality in a cost-effective manner using e.g., a turbidimeter. Turbidimeters typically use different illumination angles to measure the scattering and transmittance of light through a sample and translate these readings into a measurement based on the standard nephelometric turbidity unit (NTU). Traditional turbidimeters have high sensitivity and specificity, but they are not field-portable and require electricity to operate in field settings. Here we present a field-portable and cost effective turbidimeter that is based on a smartphone. This mobile turbidimeter contains an opto-mechanical attachment coupled to the rear camera of the smartphone, which contains two white light-emitting-diodes to illuminate the water sample, optical fibers to transmit the light collected from the sample to the camera, an external lens for image formation, and diffusers for uniform illumination of the sample. Including the smartphone, this cost-effective device weighs only ~350 g. In our mobile turbidimeter design, we combined two illumination approaches: transmittance, in which the optical fibers were placed directly below the sample cuvette at 180° with respect to the light source, and nephelometry in which the optical fibers were placed on the sides of the sample cuvette at a 90°angle with respect to the to the light source. Images of the end facets of these fiber optic cables were captured using the smart phone and processed using a custom written image processing algorithm to automatically quantify the turbidity of each sample. Using transmittance and nephelometric readings, our mobile turbidimeter achieved accurate measurements over a large dynamic range, from 0.3 NTU to 2000 NTU. The accurate performance of our smartphone-based turbidimeter was also confirmed with various water samples collected in Los Angeles (USA), bacteria spiked water samples, as well as diesel fuel contaminated water samples. Having a detection limit of ~0.3 NTU, this cost-effective smartphone-based turbidimeter can be a useful analytical tool for screening of water quality in resource limited settings.