Broadly Available Imaging Devices Enable High-Quality Low-Cost Photometry
Broadly Available Imaging Devices Enable High-Quality Low-Cost Photometry
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DOI：
10.1021/acs.analchem.5b01612
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发表时间：
2015-09-15
影响因子：
7.4
通讯作者：
Whitesides, George M.
中科院分区：
文献类型：
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作者：
Christodouleas, Dionysios C.;Nemiroski, Alex;Whitesides, George M.
这篇论文证明，对于资源有限环境中的应用，许多中心实验室中用于平行测量样品吸光度的昂贵的微孔板光度计可以被基于廉价和普遍存在的消费电子设备（例如，扫描仪和手机摄像头）。两个设备，（i）在透射模式下操作的平板扫描仪和（ii）基于相机的光度计（由手机相机、平面光源和纸板盒构成），演示了该概念。这些设备从一侧照射微量滴定板中的样品，并使用扫描仪/相机的基于RGB的成像传感器来测量传输到另一侧的光。样品的宽带吸光度（RGB分辨吸光度）可以使用每个微孔仅三个像素的RGB颜色值来计算。严格的理论分析建立了样品的吸收光谱与其相应的RGB分辨吸收之间的明确关系。使用这些低成本光度计对不同染料进行测量的线性度和精度，这些染料在可见光谱范围内吸收，以及分析的显色产物（例如，酶法、ELISA）证明了这些低成本光度计可以可靠地用于广泛的化学和生物化学分析。平行且低成本地对液体样品进行吸光度的准确测量的能力将使得通常保留给装备精良的诊所和实验室的测试能够在资源和专业知识有限的情况下进行。
This paper demonstrates that, for applications in resource-limited environments, expensive microplate spectrophotometers that are used in many central laboratories for parallel measurement of absorbance of samples can be replaced by photometers based on inexpensive and ubiquitous, consumer electronic devices (e.g., scanners and cell-phone cameras). Two devices, (i) a flatbed scanner operating in transmittance mode and (ii) a camera-based photometer (constructed from a cell phone camera, a planar light source, and a cardboard box), demonstrate the concept. These devices illuminate samples in microtiter plates from one side and use the RGB-based imaging sensors of the scanner/camera to measure the light transmitted to the other side. The broadband absorbance of samples (RGB-resolved absorbance) can be calculated using the RGB color values of only three pixels per microwell. Rigorous theoretical analysis establishes a well-defined relationship between the absorbance spectrum of a sample and its corresponding RGB-resolved absorbance. The linearity and precision of measurements performed with these low-cost photometers on different dyes, which absorb across the range of the visible spectrum, and chromogenic products of assays (e.g., enzymatic, ELISA) demonstrate that these low-cost photometers can be used reliably in a broad range of chemical and biochemical analyses. The ability to perform accurate measurements of absorbance on liquid samples, in parallel and at low cost, would enable testing, typically reserved for well-equipped clinics and laboratories, to be performed in circumstances where resources and expertise are limited.