Data from: Portable device for the detection of colorimetric assays

AbstractIn this work, a low-cost, portable device is developed to detect colorimetric assays for in-field and point-of-care (POC) analysis. The device can rapidly detect both pH values and nitrite concentrations of 5 different samples, simultaneously. After mixing samples with specific reagents, a Hi-resolution digital camera collects a picture of the sample, and a single-board computer processes the image in real time to identify the hue-saturation-value (HSV) coordinates of the image. An internal light source reduces the effect of any ambient light so the device can accurately determine the corresponding pH values or nitrite concentrations. The device was purposefully designed to be low-cost, yet versatile and the accuracy of the results have been compared to those from a conventional method. The results obtained for pH values have a mean standard deviation of 0.03 and a correlation coefficient (R) of 0.998. The detection of nitrites is between concentrations of 0.4 to 1.6mg/L with a low detection limit of 0.2mg/L and has a mean standard deviation of 0.073 and an R-value of 0.999. The results represent the great potential of the proposed portable device as an excellent analytical tool for POC colorimetric analysis and offer broad accessibility in resource-limited settings., Usage notesResults presented in figure 7.The hue values as a function of pH values (ranging from 4 to 8) and the fitted polynomial curve.Results presented in figure 8 (a) and (b).(a) The sensor response to different nitrite concentrations in the sample, (b) nitrite concentration calibration curve (Line fitted to the experimental S values obtained for different nitrite concentrations using Griess reagents).Results presented in figure 9.A Linear relationship between the pH values obtained using the pH meter and those obtained using the portable device.Results presented in figure 10.A Linear relationship between the concentrations of the prepared nitrite solutions and those obtained using the portable device.Results presented in figure .11 (Top) and (Botoom)UV-vis measurements for nitrite concentrations (top) UV-vis spectrum for the determination of different nitrite concentration, (bottom) nitrite concentration calibration curve (Line fitted to the experimental absorbance values at 540 nm obtained for different nitrite concentrations using Griess reagents)Photocolorimeter algorithm摘要 本研究开发了一款低成本便携式设备，用于现场即时检测（point-of-care, POC）比色分析实验。该设备可同时快速检测5份不同样品的pH值与亚硝酸盐浓度。将样品与特定试剂混合后，高分辨率数码相机采集样品图像，单板计算机实时处理图像，识别图像的色相-饱和度-明度（HSV）坐标。内置光源可抵消环境光干扰，使设备能够精准测定对应的pH值或亚硝酸盐浓度。 该设备在设计上兼顾低成本与多功能性，其检测结果的准确性已与传统方法进行对比验证。pH值检测结果的平均标准偏差为0.03，相关系数（R）达0.998。亚硝酸盐检测的浓度范围为0.4至1.6mg/L，最低检测限为0.2mg/L，平均标准偏差为0.073，相关系数R为0.999。本研究开发的便携式设备展现出作为即时检测比色分析优秀工具的巨大潜力，可为资源匮乏地区提供广泛的检测便利性。 使用说明 相关结果展示如下： 图7展示了以pH值（范围4至8）为自变量的色相值变化及拟合多项式曲线。 图8(a)与(b)展示了相关结果：(a) 传感器对样品中不同亚硝酸盐浓度的响应；(b) 亚硝酸盐浓度校准曲线（基于使用格里斯试剂（Griess reagents）得到的不同亚硝酸盐浓度对应的实验S值拟合得到的直线）。 图9展示了使用pH计测得的pH值与本便携式设备测得的pH值之间的线性关系。 图10展示了配制的亚硝酸盐溶液浓度与本便携式设备测得的浓度之间的线性关系。 图11（上半部分与下半部分）展示了亚硝酸盐浓度的紫外-可见光谱检测结果：(上半部分) 不同亚硝酸盐浓度对应的紫外-可见光谱；(下半部分) 亚硝酸盐浓度校准曲线（基于使用格里斯试剂在540nm波长下得到的不同亚硝酸盐浓度对应的实验吸光度值拟合得到的直线）。 光电比色计算法