Triton Systems Inc., Chelmsford, MA 01824, USA.
Department of Chemical Engineering, University of Massachusetts Lowell, One University Avenue, Lowell, MA 01854, USA.
Mil Med. 2021 Jan 25;186(Suppl 1):716-721. doi: 10.1093/milmed/usaa473.
We developed low-cost, portable paper-based diagnostic devices for detection of human immunoglobulin M (IgM) and immunoglobulin G (IgG) in serum without any sample preparation. These devices can be used to help identify presence of diseases, used to provide rapid results (<5 minutes), readily used by untrained personnel, employed in austere environments, configured to obtain multiplexed assays, and easily disposed of.
We successfully accomplished colorimetric detection of human IgG and human IgM using a sandwich-style assay within the microfluidic paper device via vertical flow immunoassay configuration. The reaction zone in the wax printed paper layer is a small circular pattern. Gold nanoparticles conjugated with anti-human IgG and IgM antibodies have been used for colorimetric detection of IgG or IgM by naked eye. Colorimetric signal can be precisely quantified through implementation of image analysis software which can be developed as an app for a smartphone. The size of the device is 2 cm × 2 cm × 1 mm.
Colorimetric detection of human IgG was accomplished at 100 fg/mL concentration using a gold nanoparticle-conjugated anti-human IgG antibody. The developed platform has a dynamic range of IgM and IgG concentrations between 0.1 pg/mL and 100 μg/mL. These devices provided a color readout in <5 minutes using 20 µL of serum. We also demonstrated that the devices show a significant degree of ruggedness and temperature stability as they were able to provide satisfactory results (detection of 0.1 pg/mL IgG) after 14 days of long stability and shelf-life experiment at an elevated temperature of at least 50 ˚C-the shelf life can be as long as 180 days under ambient conditions for detection of 100 µg/mL IgG.
Because of the inherent simplicity of the device operation and their ease of use, there is no variation between samples and users of the device. This low-cost approach enables multiplexing with >1 measurement performed in parallel at the same time. We anticipate that because of the sensitivity, specificity, ease of use, and overall reliability, this approach will become a standard for diagnosis of diseases and health conditions.
我们开发了低成本、便携式的纸质诊断设备，用于检测血清中的人免疫球蛋白 M（IgM）和免疫球蛋白 G（IgG），无需任何样品制备。这些设备可用于帮助确定疾病的存在，提供快速结果（<5 分钟），易于未经培训的人员使用，可在恶劣环境中使用，可配置为进行多重分析，且易于处理。
我们成功地在微流控纸设备内使用夹心式测定法通过垂直流免疫测定配置实现了人 IgG 和人 IgM 的比色检测。蜡印在纸层中的反应区是一个小圆形图案。已使用与人 IgG 和 IgM 抗体偶联的金纳米颗粒通过肉眼对 IgG 或 IgM 进行比色检测。比色信号可通过实施图像分析软件进行精确量化，该软件可开发为智能手机的应用程序。设备的尺寸为 2cm×2cm×1mm。
使用与人 IgG 抗体偶联的金纳米颗粒，在 100fg/mL 浓度下实现了人 IgG 的比色检测。该开发平台具有 0.1pg/mL 至 100μg/mL 之间的 IgM 和 IgG 浓度的动态范围。这些设备使用 20μL 的血清在<5 分钟内提供了颜色读数。我们还证明，这些设备具有很高的坚固性和温度稳定性，因为它们在 14 天的长期稳定性和至少 50°C 的高温保质期实验后仍能提供令人满意的结果（检测到 0.1pg/mL IgG），在环境条件下的保质期可长达 180 天，可检测到 100μg/mL IgG。
由于设备操作固有的简单性及其易用性，设备的使用者之间不存在差异。这种低成本的方法可实现多路复用，可同时并行进行>1 次测量。我们预计，由于其灵敏度、特异性、易用性和整体可靠性，这种方法将成为疾病和健康状况诊断的标准。
