Department of Bioengineering, Micro and Nano Technology Laboratory, University of Illinois at Urbana-Champaign, 208 N. Wright Street, Urbana, IL 61801, USA.
Lab Chip. 2017 Sep 26;17(19):3246-3257. doi: 10.1039/c7lc00633k.
We demonstrate a smartphone-integrated handheld detection instrument capable of utilizing the internal rear-facing camera as a high-resolution spectrometer for measuring the colorimetric absorption spectrum, fluorescence emission spectrum, and resonant reflection spectrum from a microfluidic cartridge inserted into the measurement light path. Under user selection, the instrument gathers light from either the white "flash" LED of the smartphone or an integrated green laser diode to direct illumination into a liquid test sample or onto a photonic crystal biosensor. Light emerging from each type of assay is gathered via optical fiber and passed through a diffraction grating placed directly over the smartphone camera to generate spectra from the assay when an image is collected. Each sensing modality is associated with a unique configuration of a microfluidic "stick" containing a linear array of liquid chambers that are swiped through the instrument while the smartphone captures video and the software automatically selects spectra representative of each compartment. The system is demonstrated for representative assays in the field of point-of-care (POC) maternal and infant health: an ELISA assay for the fetal fibronectin protein used as an indicator for pre-term birth and a fluorescent assay for phenylalanine as an indicator for phenylketonuria. In each case, the TRI-analyzer is capable of achieving limits of detection that are comparable to those obtained for the same assay measured with a conventional laboratory microplate reader, demonstrating the flexibility of the system to serve as a platform for rapid, simple translation of existing commercially available biosensing assays to a POC setting.
我们展示了一种智能手机集成的手持式检测仪器，它能够利用内部后置摄像头作为高分辨率光谱仪，用于测量插入测量光路的微流控芯片的比色吸收光谱、荧光发射光谱和共振反射光谱。在用户选择下，该仪器可以从智能手机的白色“闪光灯”LED 或集成的绿色激光二极管收集光线，将其直接照射到液体测试样本或光子晶体生物传感器上。每种分析物发出的光都通过光纤收集，并通过直接放置在智能手机摄像头上方的衍射光栅传输，当采集图像时，从分析物中生成光谱。每种传感模式都与包含线性排列的液体腔室的微流“棒”的独特配置相关联，当智能手机捕获视频时，这些腔室会在仪器中滑动，并且软件会自动选择代表每个腔室的光谱。该系统在即时护理（POC）母婴健康领域的代表性分析物中进行了演示：一种用于胎儿纤维连接蛋白蛋白的 ELISA 分析物，用作早产的指标，以及一种用于苯丙氨酸的荧光分析物，用作苯丙酮尿症的指标。在每种情况下，TRI 分析仪都能够达到与使用传统实验室微孔板读取器测量相同分析物的检测限相当的检测限，这证明了该系统的灵活性，可作为一个平台，将现有的商业可用生物传感分析物快速、简单地转化为 POC 设置。
