Sanjay Sharma T, Dou Maowei, Sun Jianjun, Li XiuJun
Department of Chemistry, University of Texas at El Paso, 500 West University Ave, El Paso, Texas, 79968, USA.
Border Biomedical Research Center, University of Texas at El Paso, 500 West University Ave, El Paso, Texas, 79968, USA.
Sci Rep. 2016 Jul 26;6:30474. doi: 10.1038/srep30474.
Enzyme linked immunosorbent assay (ELISA) is one of the most widely used laboratory disease diagnosis methods. However, performing ELISA in low-resource settings is limited by long incubation time, large volumes of precious reagents, and well-equipped laboratories. Herein, we developed a simple, miniaturized paper/PMMA (poly(methyl methacrylate)) hybrid microfluidic microplate for low-cost, high throughput, and point-of-care (POC) infectious disease diagnosis. The novel use of porous paper in flow-through microwells facilitates rapid antibody/antigen immobilization and efficient washing, avoiding complicated surface modifications. The top reagent delivery channels can simply transfer reagents to multiple microwells thus avoiding repeated manual pipetting and costly robots. Results of colorimetric ELISA can be observed within an hour by the naked eye. Quantitative analysis was achieved by calculating the brightness of images scanned by an office scanner. Immunoglobulin G (IgG) and Hepatitis B surface Antigen (HBsAg) were quantitatively analyzed with good reliability in human serum samples. Without using any specialized equipment, the limits of detection of 1.6 ng/mL for IgG and 1.3 ng/mL for HBsAg were achieved, which were comparable to commercial ELISA kits using specialized equipment. We envisage that this simple POC hybrid microplate can have broad applications in various bioassays, especially in resource-limited settings.
酶联免疫吸附测定（ELISA）是应用最为广泛的实验室疾病诊断方法之一。然而，在资源匮乏地区进行ELISA检测受到孵育时间长、大量昂贵试剂以及设备完善的实验室等因素的限制。在此，我们开发了一种简单的、小型化的纸质/聚甲基丙烯酸甲酯（PMMA）混合微流控微孔板，用于低成本、高通量和即时检测（POC）传染病诊断。在流通微孔中创新性地使用多孔纸有助于快速固定抗体/抗原并高效洗涤，避免了复杂的表面修饰。顶部试剂输送通道可简单地将试剂转移至多个微孔，从而避免了重复手动移液和昂贵的机器人操作。比色ELISA结果可在一小时内通过肉眼观察到。通过计算办公室扫描仪扫描图像的亮度实现了定量分析。在人血清样本中对免疫球蛋白G（IgG）和乙型肝炎表面抗原（HBsAg）进行了定量分析，具有良好的可靠性。在不使用任何专业设备的情况下，实现了IgG检测限为1.6 ng/mL，HBsAg检测限为1.3 ng/mL，这与使用专业设备的商业ELISA试剂盒相当。我们设想这种简单的POC混合微孔板可在各种生物检测中广泛应用，尤其是在资源有限的环境中。
