Rasooly Avraham, Kostov Yordan, Bruck Hugh A
Division of Biology, Office of Science and Engineering, FDA Center for Devices and Radiological Health (CDRH), Silver Spring, MD, USA.
Methods Mol Biol. 2013;949:365-85. doi: 10.1007/978-1-62703-134-9_23.
A critical element of any Lab-on-a-Chip (LOC) is a detector; among the many detection approaches, optical detection is very widely used for biodetection. One challenge for advancing the development of LOC for biodetection has been to enhance the portability and lower the cost for Point-of-Care diagnostics, which has the potential to enhance the quality of healthcare delivery for underserved populations and for global health. We describe a simple and relatively low cost charged-coupled device (CCD)-based detector that can be integrated with a conventional microtiter plate or a portable LOC assay for various optical detection modalities including fluorescence, chemiluminescence, densitometry, and colorimetric assays. In general, the portable battery-operated CCD-based detection system consists of four modules: (1) a cooled CCD digital camera to monitor light emission, (2) a LOC or microtiter plate to perform assays, (3) a light source to illuminate the assay (such as electroluminescence (EL) or light emitting diode (LED)), and (4) a portable computer to acquire and analyze images. The configuration of the fluorescence detector presented here was designed to measure fluorogenic excitation at 490 nm and to monitor emission at 523 nm used for FITC detection.The LOC used for this detection system was fabricated with laminated object manufacturing (LOM) technology, and was designed to detection activity of botulinum neurotoxin serotype A (BoNT-A) using a fluorogenic peptide substrate (SNAP-25) for botulinum neurotoxin serotype A (BoNT-A) labeled with FITC. The limit of detection (LOD) for the CCD detector is 0.5 nM (25 ng/ml). The portable system is small and is powered by a 12 V source. The modular detector was designed with easily interchangeable LEDs, ELs, filters, lenses, and LOC, and can be used and adapted for a wide variety of densitometry, florescence and colorimetric assays.
任何芯片实验室（LOC）的一个关键要素是检测器；在众多检测方法中，光学检测在生物检测中应用极为广泛。推动用于生物检测的LOC发展面临的一个挑战是提高即时诊断的便携性并降低成本，这有可能提高服务不足人群的医疗服务质量以及全球健康水平。我们描述了一种简单且成本相对较低的基于电荷耦合器件（CCD）的检测器，它可与传统微孔板或便携式LOC检测相结合，用于包括荧光、化学发光、光密度测定和比色测定在内的各种光学检测方式。一般来说，便携式电池供电的基于CCD的检测系统由四个模块组成：（1）一个用于监测光发射的冷却CCD数码相机，（2）一个用于进行检测的LOC或微孔板，（3）一个用于照亮检测的光源（如电致发光（EL）或发光二极管（LED）），以及（4）一台用于采集和分析图像的便携式计算机。这里展示的荧光检测器的配置旨在测量490nm处的荧光激发，并监测用于FITC检测的523nm处的发射。用于该检测系统的LOC采用分层实体制造（LOM）技术制造，旨在使用用FITC标记的A型肉毒杆菌神经毒素（BoNT-A）的荧光肽底物（SNAP-25）检测A型肉毒杆菌神经毒素（BoNT-A）的活性。CCD检测器的检测限（LOD）为0.5 nM（25 ng/ml）。该便携式系统体积小，由12V电源供电。模块化检测器设计有易于互换的LED、ELs、滤光片、透镜和LOC，可用于并适用于各种光密度测定、荧光和比色测定。
